drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index fba8b74..4b267b8 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -691,7 +691,7 @@
 	return 0;
 }
 
-static struct ethtool_ops skge_ethtool_ops = {
+static const struct ethtool_ops skge_ethtool_ops = {
 	.get_settings	= skge_get_settings,
 	.set_settings	= skge_set_settings,
 	.get_drvinfo	= skge_get_drvinfo,