audio: fix memory leak reported by ASAN

Signed-off-by: NKővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: ed35e9e72aa77c9376e9c8a8f3a5443703fe6fbe.1566168923.git.DirtY.iCE.hu@gmail.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

audio/audio.c

@@ -1345,6 +1345,12 @@ static void free_audio_state(AudioState *s)
         qapi_free_Audiodev(s->dev);
         s->dev = NULL;
     }
+
+    if (s->ts) {
+        timer_free(s->ts);
+        s->ts = NULL;
+    }
+
     g_free(s);
 }