drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index eae5a55..b158de2 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -5429,7 +5429,7 @@
 	return 0;
 }
 
-static struct ethtool_ops bnx2_ethtool_ops = {
+static const struct ethtool_ops bnx2_ethtool_ops = {
 	.get_settings		= bnx2_get_settings,
 	.set_settings		= bnx2_set_settings,
 	.get_drvinfo		= bnx2_get_drvinfo,