esp6: remove a duplicative condition

Fixes coccicheck warnings:
./net/ipv6/esp6_offload.c:319:32-34:
WARNING !A || A && B is equivalent to !A || B
Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/ipv6/esp6_offload.c

@@ -316,7 +316,7 @@ static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features
 	esp.plen = esp.clen - skb->len - esp.tfclen;
 	esp.tailen = esp.tfclen + esp.plen + alen;
 
-	if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
+	if (!hw_offload || !skb_is_gso(skb)) {
 		esp.nfrags = esp6_output_head(x, skb, &esp);
 		if (esp.nfrags < 0)
 			return esp.nfrags;