Use addClassResourceCleanup for cleanup in identity users test

Change-Id: I180171cf6b432745c148b9880116fea5e8631581
diff --git a/tempest/api/identity/admin/v3/test_list_users.py b/tempest/api/identity/admin/v3/test_list_users.py
index 88cd8be..c69e4c8 100644
--- a/tempest/api/identity/admin/v3/test_list_users.py
+++ b/tempest/api/identity/admin/v3/test_list_users.py
@@ -47,21 +47,18 @@
         cls.domain_enabled_user = cls.users_client.create_user(
             name=u1_name, password=alt_password,
             email=cls.alt_email, domain_id=cls.domain['id'])['user']
+        cls.addClassResourceCleanup(cls.users_client.delete_user,
+                                    cls.domain_enabled_user['id'])
         cls.users.append(cls.domain_enabled_user)
         # Create default not enabled user
         u2_name = data_utils.rand_name('test_user')
         cls.non_domain_enabled_user = cls.users_client.create_user(
             name=u2_name, password=alt_password,
             email=cls.alt_email, enabled=False)['user']
+        cls.addClassResourceCleanup(cls.users_client.delete_user,
+                                    cls.non_domain_enabled_user['id'])
         cls.users.append(cls.non_domain_enabled_user)
 
-    @classmethod
-    def resource_cleanup(cls):
-        # Cleanup the users created during setup
-        for user in cls.users:
-            cls.users_client.delete_user(user['id'])
-        super(UsersV3TestJSON, cls).resource_cleanup()
-
     @decorators.idempotent_id('08f9aabb-dcfe-41d0-8172-82b5fa0bd73d')
     def test_list_user_domains(self):
         # List users with domain