Can't build with CONFIG_NETFILTER=y/m on IA64, there's a missing
#include in net/ipv6/netfilter.c

net/ipv6/netfilter.c: In function `nf_ip6_checksum':
net/ipv6/netfilter.c:92: warning: implicit declaration of function
`csum_ipv6_magic'
Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>