slub: fix leak of 'name' in sysfs_slab_add

The failure paths of sysfs_slab_add don't release the allocation of
'name' made by create_unique_id() a few lines above the context of the
diff below. Create a common exit path to make it more obvious what
needs freeing.

[[e-mail]: free the name only if !unmergeable]
Signed-off-by: Dave Jones <[e-mail]>
Signed-off-by: Vladimir Davydov <[e-mail]>
Cc: Pekka Enberg <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/slub.c

···
 
 	s->kobj.kset = cache_kset(s);
 	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
-	if (err) {
-		kobject_put(&s->kobj);
-		return err;
-	}
+	if (err)
+		goto out_put_kobj;
 
 	err = sysfs_create_group(&s->kobj, &slab_attr_group);
-	if (err) {
-		kobject_del(&s->kobj);
-		kobject_put(&s->kobj);
-		return err;
-	}
+	if (err)
+		goto out_del_kobj;
 
 #ifdef CONFIG_MEMCG_KMEM
 	if (is_root_cache(s)) {
 		s->memcg_kset = kset_create_and_add("cgroup", NULL, &s->kobj);
 		if (!s->memcg_kset) {
-			kobject_del(&s->kobj);
-			kobject_put(&s->kobj);
-			return -ENOMEM;
+			err = -ENOMEM;
+			goto out_del_kobj;
 		}
 	}
 #endif
···
 	if (!unmergeable) {
 		/* Setup first alias */
 		sysfs_slab_alias(s, s->name);
-		kfree(name);
 	}
-	return 0;
+out:
+	if (!unmergeable)
+		kfree(name);
+	return err;
+out_del_kobj:
+	kobject_del(&s->kobj);
+out_put_kobj:
+	kobject_put(&s->kobj);
+	goto out;
 }
 
 static void sysfs_slab_remove(struct kmem_cache *s)