condvars: sem_wait() -> ptw32_semwait()

[Alexander Terekhov]

G'Day,

the problem is in ptw32_cond_wait_cleanup() and 
ptw32_cond_unblock(). Both need to use something like 
ptw32_semwait() -- "Unlike sem_wait(), this routine is 
non-cancelable". The rest of CV stuff seems to be okay,
in this respect.

regards,
alexander.

P.S. No patch due to "me boycotting" the [L]GPL'd stuff.