dri2: reply to client for WaitMSC request in any case

otherwise client would wait for reply forever and desktop appears hang.

Signed-off-by: Flora Cui <flora.cui@amd.com>
Acked-by: Feifei Xu <Feifei.Xu@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

src/amdgpu_dri2.c

@@ -1062,6 +1062,9 @@ static int amdgpu_dri2_schedule_wait_msc(ClientPtr client, DrawablePtr draw,
 out_complete:
 	if (wait_info)
 		amdgpu_dri2_deferred_event(NULL, 0, wait_info);
+	else
+		DRI2WaitMSCComplete(client, draw, 0, 0, 0);
+
 	return TRUE;
 }