drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/ehea/ehea_ethtool.c b/drivers/net/ehea/ehea_ethtool.c
index 6906af6..82eb2fb 100644
--- a/drivers/net/ehea/ehea_ethtool.c
+++ b/drivers/net/ehea/ehea_ethtool.c
@@ -270,7 +270,7 @@
 	kfree(cb6);
 }
 
-struct ethtool_ops ehea_ethtool_ops = {
+const struct ethtool_ops ehea_ethtool_ops = {
 	.get_settings = ehea_get_settings,
 	.get_drvinfo = ehea_get_drvinfo,
 	.get_msglevel = ehea_get_msglevel,