pktcdvd: add kobject_put when kobject register fails

In kobject_register, the kobject reference is get in kobject_init, and then
kobject_add. If kobject_add fail, it will only cleanup the reference got
by itself.

Signed-off-by: Dave Young <[e-mail]>
Reviewed-by: Pekka Enberg <[e-mail]>
Cc: Greg KH <[e-mail]>
Cc: Peter Osterlund <[e-mail]>
Cc: Jens Axboe <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/block/pktcdvd.c

···
 	p->kobj.parent = parent;
 	p->kobj.ktype = ktype;
 	p->pd = pd;
-	if (kobject_register(&p->kobj) != 0)
+	if (kobject_register(&p->kobj) != 0) {
+		kobject_put(&p->kobj);
 		return NULL;
+	}
 	return p;
 }
 /*