sfc: Enable RX checksum offload for packets not handled by GRO

Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/rx.c

@@ -598,6 +598,8 @@ static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
 
 	/* Set the SKB flags */
 	skb_checksum_none_assert(skb);
+	if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED))
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
 	if (channel->type->receive_skb)
 		if (channel->type->receive_skb(channel, skb))