iwlwifi: fix potential lock inversion deadlock

This is a change to a previous patch ("iwlwifi: 3945 split tx_complete
to command and packet function") to ensure we do not have hardirq safe
locks (priv->lock in this case) depend on hardirq unsafe locks.

We only call iwl3945_tx_queue_reclaim while in a tasklet so we have to use
the irqsafe version of the function.

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

drivers/net/wireless/iwlwifi/iwl-3945.c

@@ -283,7 +283,7 @@ static void iwl3945_tx_queue_reclaim(struct iwl3945_priv *priv,
 		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {
 
 		tx_info = &txq->txb[txq->q.read_ptr];
-		ieee80211_tx_status(priv->hw, tx_info->skb[0],
+		ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb[0],
 					    &tx_info->status);
 		tx_info->skb[0] = NULL;
 		iwl3945_hw_txq_free_tfd(priv, txq);