[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/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 394bc54..147ce49 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1527,7 +1527,7 @@
 	return NULL;
 }
 
-static int tcp_v6_checksum_init(struct sk_buff *skb)
+static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
 {
 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		if (!tcp_v6_check(skb->h.th,skb->len,&skb->nh.ipv6h->saddr,