mac80211: Don't call rate control when HW handles it

Rate control should not be called to update the tx status
when HW does the RC.

Signed-off-by: Vasanthakumar <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rate.h b/net/mac80211/rate.h
index 669dddd..998cf7a 100644
--- a/net/mac80211/rate.h
+++ b/net/mac80211/rate.h
@@ -44,6 +44,10 @@
 	struct rate_control_ref *ref = local->rate_ctrl;
 	struct ieee80211_sta *ista = &sta->sta;
 	void *priv_sta = sta->rate_ctrl_priv;
+
+	if (!ref)
+		return;
+
 	ref->ops->tx_status(ref->priv, sband, ista, priv_sta, skb);
 }