kset: convert kernel_subsys to use kset_create

Dynamically create the kset instead of declaring it statically.  We also
rename kernel_subsys to kernel_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 6672142..5ce92c3 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -432,7 +432,7 @@
 {
 	int retval;
 
-	debug_kobj = kobject_create_and_add("debug", &kernel_subsys.kobj);
+	debug_kobj = kobject_create_and_add("debug", &kernel_kset->kobj);
 	if (!debug_kobj)
 		return -EINVAL;