mac80211: fix warn, enum may be used uninitialized

regression introduced by b8d92c9c141ee3dc9b3537b1f0ffb4a54ea8d9b2

In function ‘ieee80211_work_rx_queued_mgmt’:
warning: ‘rma’ may be used uninitialized in this function

this re-adds default value WORK_ACT_NONE back to rma

Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index be3d4a69..b025dc7 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -715,7 +715,7 @@
 	struct ieee80211_rx_status *rx_status;
 	struct ieee80211_mgmt *mgmt;
 	struct ieee80211_work *wk;
-	enum work_action rma;
+	enum work_action rma = WORK_ACT_NONE;
 	u16 fc;
 
 	rx_status = (struct ieee80211_rx_status *) skb->cb;