[0.4.8][MSWSOCK] Fix 3 MSVC2010SP1 x86 dbg warnings C4146 CORE-18104

[0.4.8][MSWSOCK] Fix 3 MSVC2010SP1 x86 dbg warnings C4146 CORE-18104

can be observed with MSVC 2010SP1 (16.0.40219.1) x86 target in dbg configuation:
C:\047rls\reactos\dll\win32\mswsock\mswhelper.c(264) : warning C4146: unary minus operator applied to unsigned type, result still unsigned
C:\047rls\reactos\dll\win32\mswsock\mswhelper.c(280) : warning C4146: unary minus operator applied to unsigned type, result still unsigned
C:\047rls\reactos\dll\win32\mswsock\mswhelper.c(326) : warning C4146: unary minus operator applied to unsigned type, result still unsigned

Fix is a partial pick of 0.4.10-dev-409-g 0f8439aa71c3349282eea09e001965744292eaaa

No warnings left in this module.