main_notify: use pthread_cond_signal instead of broadcast

signal is all we need since we only have one waiter and
likely faster

git-svn-id: https://svn.musicpd.org/mpd/trunk@7349 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/main_notify.c

@@ -96,7 +96,7 @@ static void wakeup_via_cond(void)
 
 	if (ret == EBUSY)
 		return; /* nope, no need to wakeup at all */
-	pthread_cond_broadcast(&main_wakeup);
+	pthread_cond_signal(&main_wakeup);
 	pthread_mutex_unlock(&main_wakeup_mutex);
 }