b44: use dev_kfree_skb() in b44_tx()

b44_tx() is run from softirq handler, it can use dev_kfree_skb() instead
of dev_kfree_skb_irq()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/b44.c

@@ -610,7 +610,7 @@ static void b44_tx(struct b44 *bp)
 				 skb->len,
 				 DMA_TO_DEVICE);
 		rp->skb = NULL;
-		dev_kfree_skb_irq(skb);
+		dev_kfree_skb(skb);
 	}
 
 	bp->tx_cons = cons;