[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/netfilter.c b/net/ipv4/netfilter.c
index e49441a..b797a37 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -172,7 +172,7 @@
 	case CHECKSUM_COMPLETE:
 		if (hook != NF_IP_PRE_ROUTING && hook != NF_IP_LOCAL_IN)
 			break;
-		if ((protocol == 0 && !(u16)csum_fold(skb->csum)) ||
+		if ((protocol == 0 && !csum_fold(skb->csum)) ||
 		    !csum_tcpudp_magic(iph->saddr, iph->daddr,
 			    	       skb->len - dataoff, protocol,
 				       skb->csum)) {