[IPV6]: Generalise some functions

Using sk->sk_protocol instead of IPPROTO_TCP.

Will be used by DCCPv6 in the next changesets.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 7d3e86d..69a0dec 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -297,6 +297,8 @@
 	struct ipv6_pinfo inet6;
 };
 
+extern int inet6_sk_rebuild_header(struct sock *sk);
+
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
 {