kobject: make kobject_namespace take a const *

kobject_namespace() should take a const *kobject as it does not modify
the kobject passed to it. Change that, and the functions
kobj_child_ns_ops() and kobj_ns_ops() needed to also be changed to const
*.

Acked-by: Rafael J. Wysocki <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/kobject.h

···
 						struct kobject *kobj);
 extern void kobject_put(struct kobject *kobj);
 
-extern const void *kobject_namespace(struct kobject *kobj);
+extern const void *kobject_namespace(const struct kobject *kobj);
 extern void kobject_get_ownership(const struct kobject *kobj,
 				  kuid_t *uid, kgid_t *gid);
 extern char *kobject_get_path(const struct kobject *kobj, gfp_t flag);

include/linux/kobject_ns.h

···
 
 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
 int kobj_ns_type_registered(enum kobj_ns_type type);
-const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent);
-const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj);
+const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent);
+const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj);
 
 bool kobj_ns_current_may_mount(enum kobj_ns_type type);
 void *kobj_ns_grab_current(enum kobj_ns_type type);

lib/kobject.c

···
  * and thus @kobj should have a namespace tag associated with it.  Returns
  * %NULL otherwise.
  */
-const void *kobject_namespace(struct kobject *kobj)
+const void *kobject_namespace(const struct kobject *kobj)
 {
 	const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
 
···
 	return registered;
 }
 
-const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
+const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent)
 {
 	const struct kobj_ns_type_operations *ops = NULL;
 
···
 	return ops;
 }
 
-const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
+const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj)
 {
 	return kobj_child_ns_ops(kobj->parent);
 }