signal: fix memory access

[opencv-alalek]

fixup #3613

failed weekly validation:

• http://pullrequest.opencv.org/buildbot/builders/4_x-contrib_coverage-lin64-debug/builds/100049
• http://pullrequest.opencv.org/buildbot/builders/4_x-contrib_valgrind-lin64-debug/builds/100049

Caused by memory access errors in AVX mode.

Perf report:

Name of Test	scalar base	SSE42 base	Scalar PATCH	SSE42 PATCH	AVX2 PATCH
resample_sin_signal::TestResampleFunc::(1234, 16000, 16000)	0.000	0.000	0.000	0.000	0.000
resample_sin_signal::TestResampleFunc::(1234, 16000, 32000)	0.043	0.047	0.044	0.043	0.032
resample_sin_signal::TestResampleFunc::(1234, 16000, 44100)	0.055	0.054	0.052	0.052	0.035
resample_sin_signal::TestResampleFunc::(1234, 16000, 48000)	0.057	0.055	0.054	0.052	0.037
resample_sin_signal::TestResampleFunc::(1234, 32000, 16000)	0.036	0.028	0.003	0.003	0.001
resample_sin_signal::TestResampleFunc::(1234, 32000, 32000)	0.000	0.000	0.000	0.000	0.000
resample_sin_signal::TestResampleFunc::(1234, 32000, 44100)	0.039	0.062	0.038	0.038	0.030
resample_sin_signal::TestResampleFunc::(1234, 32000, 48000)	0.043	0.041	0.038	0.040	0.030
resample_sin_signal::TestResampleFunc::(1234, 44100, 16000)	0.032	0.027	0.002	0.002	0.001
resample_sin_signal::TestResampleFunc::(1234, 44100, 32000)	0.039	0.033	0.032	0.032	0.027
resample_sin_signal::TestResampleFunc::(1234, 44100, 44100)	0.000	0.000	0.000	0.000	0.000
resample_sin_signal::TestResampleFunc::(1234, 44100, 48000)	0.046	0.037	0.036	0.035	0.028
resample_sin_signal::TestResampleFunc::(1234, 48000, 16000)	0.026	0.027	0.002	0.002	0.001
resample_sin_signal::TestResampleFunc::(1234, 48000, 32000)	0.031	0.033	0.033	0.031	0.027
resample_sin_signal::TestResampleFunc::(1234, 48000, 44100)	0.034	0.035	0.034	0.034	0.028
resample_sin_signal::TestResampleFunc::(1234, 48000, 48000)	0.000	0.000	0.000	0.000	0.000
resample_sin_signal::TestResampleFunc::(12345, 16000, 16000)	0.001	0.001	0.001	0.001	0.001
resample_sin_signal::TestResampleFunc::(12345, 16000, 32000)	0.259	0.259	0.246	0.230	0.126
resample_sin_signal::TestResampleFunc::(12345, 16000, 44100)	0.339	0.353	0.338	0.326	0.172
resample_sin_signal::TestResampleFunc::(12345, 16000, 48000)	0.380	0.384	0.365	0.357	0.187
resample_sin_signal::TestResampleFunc::(12345, 32000, 16000)	0.058	0.058	0.032	0.032	0.011
resample_sin_signal::TestResampleFunc::(12345, 32000, 32000)	0.001	0.001	0.001	0.001	0.001
resample_sin_signal::TestResampleFunc::(12345, 32000, 44100)	0.170	0.177	0.164	0.155	0.083
resample_sin_signal::TestResampleFunc::(12345, 32000, 48000)	0.190	0.190	0.176	0.168	0.088
resample_sin_signal::TestResampleFunc::(12345, 44100, 16000)	0.050	0.050	0.023	0.023	0.008
resample_sin_signal::TestResampleFunc::(12345, 44100, 32000)	0.107	0.107	0.098	0.096	0.057
resample_sin_signal::TestResampleFunc::(12345, 44100, 44100)	0.001	0.001	0.001	0.001	0.001
resample_sin_signal::TestResampleFunc::(12345, 44100, 48000)	0.146	0.146	0.135	0.133	0.073
resample_sin_signal::TestResampleFunc::(12345, 48000, 16000)	0.049	0.049	0.021	0.021	0.008
resample_sin_signal::TestResampleFunc::(12345, 48000, 32000)	0.101	0.101	0.092	0.090	0.055
resample_sin_signal::TestResampleFunc::(12345, 48000, 44100)	0.128	0.128	0.118	0.115	0.063
resample_sin_signal::TestResampleFunc::(12345, 48000, 48000)	0.001	0.001	0.001	0.001	0.001
resample_sin_signal::TestResampleFunc::(123456, 16000, 16000)	0.010	0.008	0.009	0.009	0.009
resample_sin_signal::TestResampleFunc::(123456, 16000, 32000)	2.274	2.272	2.067	2.002	0.901
resample_sin_signal::TestResampleFunc::(123456, 16000, 44100)	3.108	3.095	2.844	2.766	1.234
resample_sin_signal::TestResampleFunc::(123456, 16000, 48000)	3.699	3.830	3.656	3.480	1.942
resample_sin_signal::TestResampleFunc::(123456, 32000, 16000)	0.353	0.338	0.321	0.320	0.113
resample_sin_signal::TestResampleFunc::(123456, 32000, 32000)	0.009	0.008	0.009	0.009	0.009
resample_sin_signal::TestResampleFunc::(123456, 32000, 44100)	1.514	1.456	1.433	1.390	0.628
resample_sin_signal::TestResampleFunc::(123456, 32000, 48000)	1.661	1.577	1.556	1.507	0.684
resample_sin_signal::TestResampleFunc::(123456, 44100, 16000)	0.268	0.280	0.233	0.233	0.082
resample_sin_signal::TestResampleFunc::(123456, 44100, 32000)	0.813	0.843	0.763	0.741	0.339
resample_sin_signal::TestResampleFunc::(123456, 44100, 44100)	0.009	0.009	0.008	0.009	0.009
resample_sin_signal::TestResampleFunc::(123456, 44100, 48000)	1.145	1.185	1.091	1.103	0.500
resample_sin_signal::TestResampleFunc::(123456, 48000, 16000)	0.253	0.253	0.205	0.214	0.075
resample_sin_signal::TestResampleFunc::(123456, 48000, 32000)	0.752	0.722	0.677	0.683	0.326
resample_sin_signal::TestResampleFunc::(123456, 48000, 44100)	1.010	1.015	0.961	0.934	0.423
resample_sin_signal::TestResampleFunc::(123456, 48000, 48000)	0.009	0.009	0.009	0.009	0.009
resample_sin_signal::TestResampleFunc::(1234567, 16000, 16000)	0.167	0.163	0.157	0.163	0.157
resample_sin_signal::TestResampleFunc::(1234567, 16000, 32000)	23.313	23.287	20.064	20.249	9.208
resample_sin_signal::TestResampleFunc::(1234567, 16000, 44100)	32.068	32.063	27.914	28.159	12.996
resample_sin_signal::TestResampleFunc::(1234567, 16000, 48000)	38.100	38.339	36.686	37.184	20.452
resample_sin_signal::TestResampleFunc::(1234567, 32000, 16000)	3.183	3.183	3.087	3.208	1.136
resample_sin_signal::TestResampleFunc::(1234567, 32000, 32000)	0.156	0.156	0.157	0.163	0.157
resample_sin_signal::TestResampleFunc::(1234567, 32000, 44100)	14.817	14.790	13.699	13.876	6.200
resample_sin_signal::TestResampleFunc::(1234567, 32000, 48000)	16.876	16.181	14.920	15.097	6.734
resample_sin_signal::TestResampleFunc::(1234567, 44100, 16000)	2.481	2.483	2.329	2.287	0.856
resample_sin_signal::TestResampleFunc::(1234567, 44100, 32000)	8.065	7.940	7.454	7.294	3.358
resample_sin_signal::TestResampleFunc::(1234567, 44100, 44100)	0.156	0.163	0.157	0.157	0.156
resample_sin_signal::TestResampleFunc::(1234567, 44100, 48000)	11.800	11.863	10.821	10.891	4.855
resample_sin_signal::TestResampleFunc::(1234567, 48000, 16000)	2.420	2.421	2.138	2.137	0.765
resample_sin_signal::TestResampleFunc::(1234567, 48000, 32000)	7.267	7.424	6.831	6.698	2.956
resample_sin_signal::TestResampleFunc::(1234567, 48000, 44100)	9.975	9.968	9.158	8.988	4.122
resample_sin_signal::TestResampleFunc::(1234567, 48000, 48000)	0.157	0.157	0.163	0.164	0.163
resample_sin_signal::TestResampleFunc::(12345678, 16000, 16000)	1.859	2.108	1.855	2.120	2.123
resample_sin_signal::TestResampleFunc::(12345678, 16000, 32000)	273.751	263.925	239.120	233.167	138.162
resample_sin_signal::TestResampleFunc::(12345678, 16000, 44100)	371.474	365.184	329.526	320.987	190.407
resample_sin_signal::TestResampleFunc::(12345678, 16000, 48000)	402.836	402.261	369.109	363.213	207.446
resample_sin_signal::TestResampleFunc::(12345678, 32000, 16000)	40.975	40.527	29.880	29.552	11.333
resample_sin_signal::TestResampleFunc::(12345678, 32000, 32000)	1.853	2.107	1.870	2.105	2.100
resample_sin_signal::TestResampleFunc::(12345678, 32000, 44100)	194.307	191.006	165.158	162.613	94.648
resample_sin_signal::TestResampleFunc::(12345678, 32000, 48000)	209.484	202.622	179.942	181.200	102.773
resample_sin_signal::TestResampleFunc::(12345678, 44100, 16000)	33.829	33.778	22.042	21.450	8.263
resample_sin_signal::TestResampleFunc::(12345678, 44100, 32000)	109.970	111.001	88.783	84.831	50.410
resample_sin_signal::TestResampleFunc::(12345678, 44100, 44100)	1.852	2.109	1.848	2.124	2.116
resample_sin_signal::TestResampleFunc::(12345678, 44100, 48000)	159.940	155.456	132.558	127.770	75.206
resample_sin_signal::TestResampleFunc::(12345678, 48000, 16000)	33.621	32.356	19.788	19.706	7.316
resample_sin_signal::TestResampleFunc::(12345678, 48000, 32000)	99.478	94.011	78.643	77.825	45.481
resample_sin_signal::TestResampleFunc::(12345678, 48000, 44100)	137.322	135.361	108.514	107.689	63.354
resample_sin_signal::TestResampleFunc::(12345678, 48000, 48000)	1.795	2.048	1.837	2.047	2.048