[IPV4/IPV6]: Use csum_sub() instead of csum_block_sub() w/zero 3rd arg.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_output.c

@@ -881,8 +881,8 @@ int ip_append_data(struct sock *sk,
 				skb->csum = skb_copy_and_csum_bits(
 					skb_prev, maxfraglen,
 					data + transhdrlen, fraggap, 0);
-				skb_prev->csum = csum_block_sub(
-					skb_prev->csum, skb->csum, 0);
+				skb_prev->csum = csum_sub(skb_prev->csum,
+							  skb->csum);
 				data += fraggap;
 				skb_trim(skb_prev, maxfraglen);
 			}
@@ -1065,8 +1065,8 @@ ssize_t	ip_append_page(struct sock *sk, struct page *page,
 				skb->csum = skb_copy_and_csum_bits(
 					skb_prev, maxfraglen,
 					data, fraggap, 0);
-				skb_prev->csum = csum_block_sub(
-					skb_prev->csum, skb->csum, 0);
+				skb_prev->csum = csum_sub(skb_prev->csum,
+							  skb->csum);
 				skb_trim(skb_prev, maxfraglen);
 			}
 

net/ipv6/ip6_output.c

@@ -977,8 +977,8 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offse
 				skb->csum = skb_copy_and_csum_bits(
 					skb_prev, maxfraglen,
 					data + transhdrlen, fraggap, 0);
-				skb_prev->csum = csum_block_sub(
-					skb_prev->csum, skb->csum, 0);
+				skb_prev->csum = csum_sub(skb_prev->csum,
+							  skb->csum);
 				data += fraggap;
 				skb_trim(skb_prev, maxfraglen);
 			}