net: emaclite: don't call dev_kfree_skb() under spin_lock_irqsave()

It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.

It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.

In this case, dev_kfree_skb() is called in xemaclite_tx_timeout() to
drop the SKB, when tx timeout, so replace it with dev_kfree_skb_irq().

Fixes: bb81b2dd ("net: add Xilinx emac lite device driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/xilinx_emaclite.c

@@ -536,7 +536,7 @@ static void xemaclite_tx_timeout(struct net_device *dev, unsigned int txqueue)
 	xemaclite_enable_interrupts(lp);
 
 	if (lp->deferred_skb) {
-		dev_kfree_skb(lp->deferred_skb);
+		dev_kfree_skb_irq(lp->deferred_skb);
 		lp->deferred_skb = NULL;
 		dev->stats.tx_errors++;
 	}