InitializeCriticalSectionAndSpinCount returns a nonzero value on success,
and some codecs (notably VP7) seemingly got confused when it didn't, if and
only if we tried to emulate NT or newer.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@30913 b3059339-0415-0410-9bf9-f77b7e298cf2