EmulatorPkg/Win/Host: Use safe function _vsnprintf_s()

Update SecPrint() to use _vsnprintf_s() instead of
_vsnprintf() that is a safe function and allows the
defines _CRT_SECURE_NO_WARNINGS and _CRT_SECURE_NO_DEPRECATE
to be removed from WinHost builds.

Signed-off-by: Michael D Kinney <[email protected]>

EmulatorPkg/Win/Host/WinHost.c

@@ -190,7 +190,7 @@ SecPrint (
 
   va_start (Marker, Format);
 
-  _vsnprintf (Buffer, sizeof (Buffer), Format, Marker);
+  _vsnprintf_s (Buffer, sizeof (Buffer), sizeof (Buffer) - 1, Format, Marker);
 
   va_end (Marker);