sfc: Move test of rx_checksum_enabled from nic.c to rx.c

This is preparation for using the generic netdev features interface,
and should have no effect in itself.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index c0fdb59..fb402c5 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -605,6 +605,9 @@
 		skb_record_rx_queue(skb, channel->channel);
 	}
 
+	if (unlikely(!efx->rx_checksum_enabled))
+		checksummed = false;
+
 	if (likely(checksummed || rx_buf->is_page)) {
 		efx_rx_packet_gro(channel, rx_buf, eh, checksummed);
 		return;