[NET]: Treat CHECKSUM_PARTIAL as CHECKSUM_UNNECESSARY

When a transmitted packet is looped back directly, CHECKSUM_PARTIAL
maps to the semantics of CHECKSUM_UNNECESSARY.  Therefore we should
treat it as such in the stack.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 634885b..1d377d1 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -154,7 +154,7 @@
 	desc.offset = sizeof(struct udphdr);
 	desc.count = skb->len - desc.offset;
 
-	if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+	if (skb_csum_unnecessary(skb))
 		goto no_checksum;
 
 	desc.csum = csum_partial(skb->data, desc.offset, skb->csum);