ip_gre: allow CSUM capable devices to handle packets

If device is not able to handle checksumming it will
be handled in dev_xmit

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index a56f118..cdc31ac 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -745,12 +745,9 @@
 			goto error;
 		skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
 		return skb;
-	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		err = skb_checksum_help(skb);
-		if (unlikely(err))
-			goto error;
 	}
-	skb->ip_summed = CHECKSUM_NONE;
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		skb->ip_summed = CHECKSUM_NONE;
 
 	return skb;