mac80211: fix a potential rate control related crash

SVN-Revision: 30388

package/mac80211/patches/300-pending_work.patch

@@ -253,3 +253,14 @@
  	WLAN_STA_CLEAR_PS_FILT,
  	WLAN_STA_MFP,
  	WLAN_STA_BLOCK_BA,
+--- a/net/mac80211/rate.h
++++ b/net/mac80211/rate.h
+@@ -37,7 +37,7 @@ static inline void rate_control_tx_statu
+ 	struct ieee80211_sta *ista = &sta->sta;
+ 	void *priv_sta = sta->rate_ctrl_priv;
+ 
+-	if (!ref)
++	if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
+ 		return;
+ 
+ 	ref->ops->tx_status(ref->priv, sband, ista, priv_sta, skb);