mac80211: remove irq disabling for sta lock

All other places except one in the TX path, which
has BHs disabled, and it also cannot be locked from
interrupts so disabling IRQs is not necessary.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/tx.c

@@ -1144,13 +1144,12 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 
 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
-		unsigned long flags;
 		struct tid_ampdu_tx *tid_tx;
 
 		qc = ieee80211_get_qos_ctl(hdr);
 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 
-		spin_lock_irqsave(&tx->sta->lock, flags);
+		spin_lock(&tx->sta->lock);
 		/*
 		 * XXX: This spinlock could be fairly expensive, but see the
 		 *	comment in agg-tx.c:ieee80211_agg_tx_operational().
@@ -1175,7 +1174,7 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 			__skb_queue_tail(&tid_tx->pending, skb);
 		}
-		spin_unlock_irqrestore(&tx->sta->lock, flags);
+		spin_unlock(&tx->sta->lock);
 
 		if (unlikely(queued))
 			return TX_QUEUED;