[patch] segv on use-after-free in dsound/buffer.c

[Yuriy Kaminskiy]

Hello!
    One of games rarely crashed with segv in line 86 of dsound/buffer.c:
85:      IDirectSoundBuffer_Release((LPDIRECTSOUNDBUFFER)This->dsb);
86:      This->dsb->notify = NULL;
    (sorry, I failed to save actual backtrace at the time). This looks 
like typical assign-after-free bug. I've applied attached patch 
(wine-1.1.7, now on 1.1.19), no crashes so far (btw, similar 
*Secodary*Release method down in code uses proper order - 
assign-NULL-then-release).