mac80211: fix RCU locking in __ieee80211_rx_handle_packet

Commit c7a51bda ("mac80211: restructure __ieee80211_rx") extracted
__ieee80211_rx_handle_packet out of __ieee80211_rx and hence changed
the locking rules for __ieee80211_rx_handle_packet(), it is now
invoked under RCU lock. There is, however, one instance left where
it contains an rcu_read_unlock() in an error path, which is a bug.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -1730,7 +1730,6 @@ void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, struct sk_buff *skb,
 		ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
 					     rx.sta);
 		sta_info_put(sta);
-		rcu_read_unlock();
 		return;
 	}