audio: do not run each backend in audio_run

audio_run is called manually by alsa and oss backends when polling.
In this case only the requesting backend should be run, not all of them.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 10221fcea2028fa18d95cf531526ffe3b1d9b21a.1566168923.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/audio/audio.c b/audio/audio.c
index 3826769..bc9ac25 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -837,7 +837,7 @@
     }
     s->timer_last = now;
 
-    audio_run("timer");
+    audio_run(s, "timer");
     audio_reset_timer(s);
 }
 
@@ -1239,15 +1239,11 @@
     }
 }
 
-void audio_run (const char *msg)
+void audio_run(AudioState *s, const char *msg)
 {
-    AudioState *s;
-
-    QTAILQ_FOREACH(s, &audio_states, list) {
-        audio_run_out(s);
-        audio_run_in(s);
-        audio_run_capture(s);
-    }
+    audio_run_out(s);
+    audio_run_in(s);
+    audio_run_capture(s);
 
 #ifdef DEBUG_POLL
     {