net: ipv6: remove unused code in ipv6_find_hdr()

Storing the left length of skb into 'len' actually has no effect
so we can remove it.
Signed-off-by: NLin Zhang <xiaolou4617@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/exthdrs_core.c

@@ -187,7 +187,6 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 {
 	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
 	u8 nexthdr = ipv6_hdr(skb)->nexthdr;
-	unsigned int len;
 	bool found;
 
 	if (fragoff)
@@ -204,7 +203,6 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 		start = *offset + sizeof(struct ipv6hdr);
 		nexthdr = ip6->nexthdr;
 	}
-	len = skb->len - start;
 
 	do {
 		struct ipv6_opt_hdr _hdr, *hp;
@@ -273,7 +271,6 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 
 		if (!found) {
 			nexthdr = hp->nexthdr;
-			len -= hdrlen;
 			start += hdrlen;
 		}
 	} while (!found);