kobject: convert kernel_kset to be a kobject

kernel_kset does not need to be a kset, but a much simpler kobject now
that we have kobj_attributes.

We also rename kernel_kset to kernel_kobj 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>

security/inode.c

@@ -321,7 +321,7 @@ static int __init securityfs_init(void)
 {
 	int retval;
 
-  	security_kobj = kobject_create_and_add("security", &kernel_kset->kobj);
+	security_kobj = kobject_create_and_add("security", kernel_kobj);
 	if (!security_kobj)
 		return -EINVAL;