mac80211: add ieee80211_sdata_running

Instead of always using netif_running(sdata->dev)
use ieee80211_sdata_running(sdata) now which is
just an inline containing netif_running() for now.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index d442674..e93bc55 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -212,7 +212,7 @@
 	}
 
 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
-		if (local->quiescing || !netif_running(sdata->dev) ||
+		if (local->quiescing || !ieee80211_sdata_running(sdata) ||
 		    test_bit(SCAN_SW_SCANNING, &local->scanning)) {
 			sdata->vif.bss_conf.enable_beacon = false;
 		} else {