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/tx.c b/net/mac80211/tx.c
index ac48c86..1593a2f 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1469,7 +1469,7 @@
 
 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
 						list) {
-				if (!netif_running(tmp_sdata->dev))
+				if (!ieee80211_sdata_running(tmp_sdata))
 					continue;
 				if (tmp_sdata->vif.type != NL80211_IFTYPE_AP)
 					continue;