mac80211: advance the state machine immediately if no delay is needed

Instead of queueing the scan work again without delay just process the
next state immediately.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/scan.c

@@ -587,6 +587,11 @@ void ieee80211_scan_work(struct work_struct *work)
 		return;
 	}
 
+	/*
+	 * as long as no delay is required advance immediately
+	 * without scheduling a new work
+	 */
+	do {
 		switch (local->scan_state) {
 		case SCAN_SET_CHANNEL:
 			if (ieee80211_scan_state_set_channel(local, &next_delay))
@@ -596,6 +601,7 @@ void ieee80211_scan_work(struct work_struct *work)
 			ieee80211_scan_state_send_probe(local, &next_delay);
 			break;
 		}
+	} while (next_delay == 0);
 
 	queue_delayed_work(local->hw.workqueue, &local->scan_work,
 			   next_delay);