winvlc: cleanup

Misc code cleanup in winvlc.c.

~~Release builds include breakpad which is C++ and thus uses the C++ runtime. Developper and nightlies builds usually don't build with breakpad and thus don't rely on the same runtime to run. This brings the 2 build setup closer.

We also don't have to force the C++ runtime to link to, it's handled by autotools.~~