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/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index 114ccab..d004c35 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -2016,7 +2016,7 @@
 	}
 }
 
-static struct ethtool_ops igb_ethtool_ops = {
+static const struct ethtool_ops igb_ethtool_ops = {
 	.get_settings           = igb_get_settings,
 	.set_settings           = igb_set_settings,
 	.get_drvinfo            = igb_get_drvinfo,