net: ns83820: use dev_kfree_skb_irq instead of kfree_skb

It is not allowed to call kfree_skb() from hardware interrupt
context or with interrupts being disabled, spin_lock_irqsave()
make sure always in irq disable context. So the kfree_skb()
should be replaced with dev_kfree_skb_irq().

This is detected by Coccinelle semantic patch.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/natsemi/ns83820.c

@@ -919,7 +919,7 @@ static void rx_irq(struct net_device *ndev)
 				ndev->stats.rx_dropped++;
 			}
 		} else {
-			kfree_skb(skb);
+			dev_kfree_skb_irq(skb);
 		}
 
 		nr++;