kobject: show debug info on delayed kobject release

Useful for locating buggy drivers on kernel oops.

It may add dozens of new lines to boot dmesg. DEBUG_KOBJECT_RELEASE is
hopefully only enabled in debug kernels (like maybe the Fedora rawhide
one, or at developers), so being a bit more verbose is likely ok.
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/kobject.c

@@ -592,7 +592,7 @@ static void kobject_release(struct kref *kref)
 {
 	struct kobject *kobj = container_of(kref, struct kobject, kref);
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
-	pr_debug("kobject: '%s' (%p): %s, parent %p (delayed)\n",
+	pr_info("kobject: '%s' (%p): %s, parent %p (delayed)\n",
 		 kobject_name(kobj), kobj, __func__, kobj->parent);
 	INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
 	schedule_delayed_work(&kobj->release, HZ);