compactor: fix BenchmarkDeduplicateFilter_Filter

[bboreham]

What this PR does

I noticed the benchmark results had an odd pattern:

BenchmarkDeduplicateFilter_Filter/Block-10/#00-8           36559             31444 ns/op           30191 B/op         84 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10/#01-8           12578             94630 ns/op           90644 B/op        253 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#00-8           1842            636375 ns/op          339749 B/op        831 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#01-8            534           1945411 ns/op         1020392 B/op       2494 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#02-8        3433188               351.4 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#03-8        3371540               349.4 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#00-8            28          38626635 ns/op         3510385 B/op       8527 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#01-8             8         126104427 ns/op        11433707 B/op      27722 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#02-8       3393375               349.2 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#03-8       3419830               351.9 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#04-8       3437992               349.3 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#05-8       3428716               350.4 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#00-8            1        9314033250 ns/op        67561168 B/op     164274 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#01-8            1        29501690542 ns/op       202588040 B/op    491671 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#02-8      3368296               351.9 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#03-8      3419041               350.0 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#04-8      3437418               349.9 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#05-8      3437319               348.4 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#06-8      3431043               349.1 ns/op             0 B/op          0 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#07-8      3381399               349.4 ns/op             0 B/op          0 allocs/op

The variable cases was appended to each time round, but only 0 and 1 were populated with any data.
I decided what was meant was just to have those two cases, so create a new cases for each number of blocks:

BenchmarkDeduplicateFilter_Filter/Block-10/#00-8           37465             31362 ns/op           30191 B/op         84 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10/#01-8           12716             93928 ns/op           90641 B/op        253 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#00-8           2148            538596 ns/op          302268 B/op        756 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-100/#01-8            729           1621291 ns/op          907473 B/op       2269 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#00-8            37          31086280 ns/op         3148539 B/op       7596 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-1000/#01-8            12          98316889 ns/op         9964838 B/op      24056 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#00-8            1        7379130333 ns/op        61041664 B/op     147549 allocs/op
BenchmarkDeduplicateFilter_Filter/Block-10000/#01-8            1        21718622500 ns/op       183079976 B/op    442289 allocs/op

Checklist

• Tests updated
• NA Documentation added
• NA CHANGELOG.md updated

[dimitarvdimitrov]

Thank you. LGTM