ipv6: constify the skb pointer of ipv6_find_tlv().

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

include/net/ipv6.h

@@ -945,7 +945,7 @@ enum {
 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
 		  unsigned short *fragoff, int *fragflg);
 
-int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
+int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
 
 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 				const struct ipv6_txoptions *opt,

net/ipv6/exthdrs_core.c

@@ -112,7 +112,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 }
 EXPORT_SYMBOL(ipv6_skip_exthdr);
 
-int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
+int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type)
 {
 	const unsigned char *nh = skb_network_header(skb);
 	int packet_len = skb_tail_pointer(skb) - skb_network_header(skb);