drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/3c507.c b/drivers/net/3c507.c
index 3a95605..8205a53 100644
--- a/drivers/net/3c507.c
+++ b/drivers/net/3c507.c
@@ -294,7 +294,7 @@
 
 static void hardware_send_packet(struct net_device *dev, void *buf, short length, short pad);
 static void init_82586_mem(struct net_device *dev);
-static struct ethtool_ops netdev_ethtool_ops;
+static const struct ethtool_ops netdev_ethtool_ops;
 static void init_rx_bufs(struct net_device *);
 
 static int io = 0x300;
@@ -919,7 +919,7 @@
 	debug = level;
 }
 
-static struct ethtool_ops netdev_ethtool_ops = {
+static const struct ethtool_ops netdev_ethtool_ops = {
 	.get_drvinfo		= netdev_get_drvinfo,
 	.get_msglevel		= netdev_get_msglevel,
 	.set_msglevel		= netdev_set_msglevel,