Remove unnecessary attrs from TenantNetworksDeprecationTest

There are a couple of unused attributes in the
TenantNetworksDeprecationTest class which can be removed. They
were probably there from some copy/paste of another class
that extended the base tenant networks test class.

Change-Id: I23e06c2f2b3a7d00037f137191c9df612a884888

nova/tests/unit/api/openstack/compute/test_tenant_networks.py

@@ -314,8 +314,6 @@ class TenantNetworksEnforcementV21(test.NoDBTestCase):
 
 
 class TenantNetworksDeprecationTest(test.NoDBTestCase):
-    ctrlr = networks_v21.TenantNetworkController
-    validation_error = exception.ValidationError
 
     def setUp(self):
         super(TenantNetworksDeprecationTest, self).setUp()