drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 17eb291..e891ea2 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -2012,7 +2012,7 @@
 	return 0;
 }
 
-static struct ethtool_ops b44_ethtool_ops = {
+static const struct ethtool_ops b44_ethtool_ops = {
 	.get_drvinfo		= b44_get_drvinfo,
 	.get_settings		= b44_get_settings,
 	.set_settings		= b44_set_settings,