drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/ns83820.c b/drivers/net/ns83820.c
index ff76b81..a05f6cb 100644
--- a/drivers/net/ns83820.c
+++ b/drivers/net/ns83820.c
@@ -1273,7 +1273,7 @@
 	return cfg & CFG_LNKSTS ? 1 : 0;
 }
 
-static struct ethtool_ops ops = {
+static const struct ethtool_ops ops = {
 	.get_drvinfo = ns83820_get_drvinfo,
 	.get_link = ns83820_get_link
 };