netdev: drivers should make ethtool_ops const

No need to put ethtool_ops in data, they should be const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 51e9ce4..32266fb 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -798,7 +798,7 @@
 		dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
 }
 
-static struct ethtool_ops virtnet_ethtool_ops = {
+static const struct ethtool_ops virtnet_ethtool_ops = {
 	.set_tx_csum = virtnet_set_tx_csum,
 	.set_sg = ethtool_op_set_sg,
 	.set_tso = ethtool_op_set_tso,