wan: remove some pointless conditionals before kfree_skb()

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index 0d7ba11..d276d72 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -731,8 +731,7 @@
 	 * We can safely fall back to non-dma-able memory, because we have
 	 * the cosa->bouncebuf pre-allocated.
 	 */
-	if (chan->rx_skb)
-		kfree_skb(chan->rx_skb);
+	kfree_skb(chan->rx_skb);
 	chan->rx_skb = dev_alloc_skb(size);
 	if (chan->rx_skb == NULL) {
 		printk(KERN_NOTICE "%s: Memory squeeze, dropping packet\n",