[IPV6]: Move nextheader offset to the IP6CB

Move nextheader offset to the IP6CB to make it possible to pass a
packet to ip6_input_finish multiple times and have it skip already
parsed headers. As a nice side effect this gets rid of the manual
hopopts skipping in ip6_input_finish.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/protocol.h b/include/net/protocol.h
index 63f7db9..6dc5970 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -43,7 +43,7 @@
 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
 struct inet6_protocol 
 {
-	int	(*handler)(struct sk_buff **skb, unsigned int *nhoffp);
+	int	(*handler)(struct sk_buff **skb);
 
 	void	(*err_handler)(struct sk_buff *skb,
 			       struct inet6_skb_parm *opt,