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/xen-netfront.c b/drivers/net/xen-netfront.c
index 3700c49..baa051d 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -51,7 +51,7 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/grant_table.h>
 
-static struct ethtool_ops xennet_ethtool_ops;
+static const struct ethtool_ops xennet_ethtool_ops;
 
 struct netfront_cb {
 	struct page *page;
@@ -1627,7 +1627,7 @@
 	}
 }
 
-static struct ethtool_ops xennet_ethtool_ops =
+static const struct ethtool_ops xennet_ethtool_ops =
 {
 	.set_tx_csum = ethtool_op_set_tx_csum,
 	.set_sg = xennet_set_sg,