Revert "wincng.c: fix clear memory feature compilation with mingw"

This reverts commit 2d2744efdd0497b72b3e1ff6e732aa4c0037fc43.

Autobuilds show that this did not solve the issue.
And it seems like RtlFillMemory is defined to memset,
which would be optimized out by some compilers.
1 file changed