iwlwifi: fix locking unbalance in 4965 rate scale

This patch fixes locking unbalance after adding rcu locking
for sta

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-4965-rs.c

@@ -852,19 +852,18 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,
 
 	sta = sta_info_get(local, hdr->addr1);
 
-	if (!sta || !sta->rate_ctrl_priv) {
-		rcu_read_unlock();
-		return;
-	}
+	if (!sta || !sta->rate_ctrl_priv)
+		goto out;
+
 
 	lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;
 
 	if (!priv->lq_mngr.lq_ready)
-		return;
+		goto out;
 
 	if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 	    !lq_sta->ibss_sta_added)
-		return;
+		goto out;
 
 	table = &lq_sta->lq;
 	active_index = lq_sta->active_tbl;
@@ -915,8 +914,7 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,
 		tx_resp->control.tx_rate->bitrate)) {
 		IWL_DEBUG_RATE("initial rate does not match 0x%x\n",
 				tx_mcs.rate_n_flags);
-		rcu_read_unlock();
-		return;
+		goto out;
 	}
 
 	/* Update frame history window with "failure" for each Tx retry. */
@@ -1025,6 +1023,7 @@ static void rs_tx_status(void *priv_rate, struct net_device *dev,
 
 	/* See if there's a better rate or modulation mode to try. */
 	rs_rate_scale_perform(priv, dev, hdr, sta);
+out:
 	rcu_read_unlock();
 	return;
 }
@@ -2229,8 +2228,7 @@ static void rs_get_rate(void *priv_rate, struct net_device *dev,
 	if (!ieee80211_is_data(fc) || is_multicast_ether_addr(hdr->addr1) ||
 	    !sta || !sta->rate_ctrl_priv) {
 		sel->rate = rate_lowest(local, sband, sta);
-		rcu_read_unlock();
-		return;
+		goto out;
 	}
 
 	lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;
@@ -2257,14 +2255,15 @@ static void rs_get_rate(void *priv_rate, struct net_device *dev,
 			goto done;
 	}
 
- done:
+done:
 	if ((i < 0) || (i > IWL_RATE_COUNT)) {
 		sel->rate = rate_lowest(local, sband, sta);
-		return;
+		goto out;
 	}
-	rcu_read_unlock();
 
 	sel->rate = &priv->ieee_rates[i];
+out:
+	rcu_read_unlock();
 }
 
 static void *rs_alloc_sta(void *priv, gfp_t gfp)