Speed up lbaasv2 test

If we reached the number of expected responses, return in the loop that
check for lbaas.

Change-Id: Ic18e5589a70b10aefabe22cb51891478500e8128
Related-Bug: #1617992

heat_integrationtests/scenario/test_autoscaling_lbv2.py

@@ -46,6 +46,8 @@ class AutoscalingLoadBalancerv2Test(scenario_base.ScenarioTestsBase):
             # skip unsuccessful requests
             if r.status_code == 200:
                 resp.add(r.text)
+                if len(resp) == expected_num:
+                    break
         self.assertEqual(expected_num, len(resp))
 
     def test_autoscaling_loadbalancer_neutron(self):