dsound global variable use reduction

[Robert Reif]

I looked at extending the lock to cover the callback
when it was 32 bit code and The TIME_KILL_SYNCHRNOUS
flag was set but I was concerned about the performance
hit and didn't pursue it further.

Eric Pouech wrote:

> Robert Reif a écrit :
> > Reduce the use of the dsound global variable by
> > passing address to functions.  This is in preparation
> > of supporting multiple DirectSound devices.  We can't
> > remove all uses because an mmtimer callback can be
> > called even after the timer is killed.  Windows has an
> > mmtimer flag that prevents this but wine doesn't
> > implement it.
>
> Could you be more specific on this one ?
> timeKillEvent is not 100% thread safe (I'll send a patch later on), but
> timeKillEvent in Wine is always synchronous (ie the killer is killed
> when timeKillEvent returns).