ao/wasapi: reenable the reset function

the race condition that necessitated disabling
this was fixed in
e440352313

audio/out/ao_wasapi.c

@@ -342,7 +342,7 @@ const struct ao_driver audio_out_wasapi = {
     .init      = init,
     .uninit    = uninit,
     .control   = control,
-    //.reset     = audio_reset, <- doesn't wait for audio callback to return
+    .reset     = audio_reset,
     .resume    = audio_resume,
     .list_devs = list_devs,
     .priv_size = sizeof(wasapi_state),