openvswitch: more accurate checksumming in queue_userspace_packet()

if skb carries an SCTP packet and ip_summed is CHECKSUM_PARTIAL, it needs
CRC32c in place of Internet Checksum: use skb_csum_hwoffload_help to avoid
corrupting such packets while queueing them towards userspace.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 7b17da9..9ddc9f8 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -453,7 +453,7 @@
 
 	/* Complete checksum if needed */
 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
-	    (err = skb_checksum_help(skb)))
+	    (err = skb_csum_hwoffload_help(skb, 0)))
 		goto out;
 
 	/* Older versions of OVS user space enforce alignment of the last