[NET]: Annotate callers of csum_fold() in net/*

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index 1445bb4..fac2dff 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -538,7 +538,7 @@
 
 u16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
 {
-	return (u16) csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
+	return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
 }
 
 static inline struct sk_buff *