保证oss_mutex_trylock的语义在windows平台和linux平台一致

pthread_mutex_trylock在lock成功时返回0，而TryEnterCriticalSection在lock成功时返回true
Revert "保证oss_mutex_trylock的语义在windows平台和linux平台一致"

This reverts commit 4624fcf0457edf2295e3c60bd7a71748f2ed9d4c.
oss_mutex_trylock跨平台语义一致

pthread_mutex_trylock return 0 when success & TryEnterCriticalSection
return TRUE when sucess
Merge pull request #3 from dfiver/master

oss_mutex_trylock跨平台语义一致性问题