ipv6: Use correct data types for ICMPv6 type and code

Change all the code that deals directly with ICMPv6 type and code
values to use u8 instead of a signed int as that's the actual data
type.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/protocol.h

@@ -53,7 +53,7 @@ struct inet6_protocol
 
 	void	(*err_handler)(struct sk_buff *skb,
 			       struct inet6_skb_parm *opt,
-			       int type, int code, int offset,
+			       u8 type, u8 code, int offset,
 			       __be32 info);
 
 	int	(*gso_send_check)(struct sk_buff *skb);