driver model: constify attribute groups

Let attribute group vectors be declared "const".  We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index ad91e9e..7d4c575 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -493,7 +493,7 @@
 int netdev_register_kobject(struct net_device *net)
 {
 	struct device *dev = &(net->dev);
-	struct attribute_group **groups = net->sysfs_groups;
+	const struct attribute_group **groups = net->sysfs_groups;
 
 	dev->class = &net_class;
 	dev->platform_data = net;