net: nci: remove redundant null pointer check before kfree_skb

kfree_skb has taken the null pointer into account. hence it is safe
to remove the redundant null pointer check before kfree_skb.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/nfc/nci/uart.c

@@ -192,9 +192,7 @@ static void nci_uart_tty_close(struct tty_struct *tty)
 	if (!nu)
 		return;
 
-	if (nu->tx_skb)
 	kfree_skb(nu->tx_skb);
-	if (nu->rx_skb)
 	kfree_skb(nu->rx_skb);
 
 	skb_queue_purge(&nu->tx_q);