[NET]: Annotate __skb_checksum_complete() and friends.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h
index 5b63a23..5821eb5 100644
--- a/include/linux/netfilter_ipv4.h
+++ b/include/linux/netfilter_ipv4.h
@@ -79,7 +79,7 @@
 #ifdef __KERNEL__
 extern int ip_route_me_harder(struct sk_buff **pskb, unsigned addr_type);
 extern int ip_xfrm_me_harder(struct sk_buff **pskb);
-extern unsigned int nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
+extern __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
 				   unsigned int dataoff, u_int8_t protocol);
 #endif /*__KERNEL__*/