cache: always update cached controls after running a stream control

Seems like a good idea. One possible bad effect would be slowing down
uncached controls, but they're already slow. The good thing is that
many controls make intrusive changes to the stream (at least controls
which do write accesses), so the cached parameters should be updated.

stream/cache.c

@@ -434,6 +434,7 @@ static void cache_execute_control(struct priv *s)
         cache_drop_contents(s);
     }
 
+    update_cached_controls(s);
     s->control = CACHE_CTRL_NONE;
     pthread_cond_signal(&s->wakeup);
 }