xen: simplify sysctl registration for balloon

register_sysctl_table() is a deprecated compatibility wrapper.
register_sysctl_init() can do the directory creation for you so just
use that.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>

drivers/xen/balloon.c

@@ -97,24 +97,6 @@ static struct ctl_table balloon_table[] = {
 	{ }
 };
 
-static struct ctl_table balloon_root[] = {
-	{
-		.procname	= "balloon",
-		.mode		= 0555,
-		.child		= balloon_table,
-	},
-	{ }
-};
-
-static struct ctl_table xen_root[] = {
-	{
-		.procname	= "xen",
-		.mode		= 0555,
-		.child		= balloon_root,
-	},
-	{ }
-};
-
 #else
 #define xen_hotplug_unpopulated 0
 #endif
@@ -747,7 +729,7 @@ static int __init balloon_init(void)
 #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
 	set_online_page_callback(&xen_online_page);
 	register_memory_notifier(&xen_memory_nb);
-	register_sysctl_table(xen_root);
+	register_sysctl_init("xen/balloon", balloon_table);
 #endif
 
 	balloon_add_regions();