ipv6: Pass proto to csum_ipv6_magic as __u8 instead of unsigned short

This patch updates csum_ipv6_magic so that it correctly recognizes that
protocol is a unsigned 8 bit value.

This will allow us to better understand what limitations may or may not be
present in how we handle the data.  For example there are a number of
places that call htonl on the protocol value.  This is likely not necessary
and can be replaced with a multiplication by ntohl(1) which will be
converted to a shift by the compiler.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/ia64/include/asm/checksum.h

@@ -69,7 +69,7 @@ static inline __sum16 csum_fold(__wsum csum)
 #define _HAVE_ARCH_IPV6_CSUM	1
 struct in6_addr;
 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
-	const struct in6_addr *daddr, __u32 len, unsigned short proto,
-	__wsum csum);
+			       const struct in6_addr *daddr,
+			       __u32 len, __u8 proto, __wsum csum);
 
 #endif /* _ASM_IA64_CHECKSUM_H */