Use quota_set instead of default_quota_set

In production cloud testing, tenant's quota_set may be
diffent with tenant's default_quota_set(i.e. we have changed
tenant's quota_set), so when testing creating servers with
overlimit vcpus or ram, we should get tenant's quota_set
instead of tenant's default_quota_set.

Change-Id: Id92436a3cf2ed8917ec35b985e20f8d25f5ef973
diff --git a/tempest/api/compute/admin/test_servers_negative.py b/tempest/api/compute/admin/test_servers_negative.py
index 5ff5d58..db6e682 100755
--- a/tempest/api/compute/admin/test_servers_negative.py
+++ b/tempest/api/compute/admin/test_servers_negative.py
@@ -34,6 +34,7 @@
         cls.client = cls.os_adm.servers_client
         cls.non_adm_client = cls.servers_client
         cls.flavors_client = cls.os_adm.flavors_client
+        cls.quotas_client = cls.os_adm.quotas_client
 
     @classmethod
     def resource_setup(cls):
@@ -64,8 +65,8 @@
         self.useFixture(fixtures.LockFixture('compute_quotas'))
         flavor_name = data_utils.rand_name("flavor")
         flavor_id = self._get_unused_flavor_id()
-        quota_set = (self.quotas_client.show_default_quota_set(self.tenant_id)
-                     ['quota_set'])
+        quota_set = self.quotas_client.show_quota_set(
+            self.tenant_id)['quota_set']
         ram = int(quota_set['ram'])
         if ram == -1:
             raise self.skipException("default ram quota set is -1,"
@@ -93,8 +94,8 @@
         flavor_name = data_utils.rand_name("flavor")
         flavor_id = self._get_unused_flavor_id()
         ram = 512
-        quota_set = (self.quotas_client.show_default_quota_set(self.tenant_id)
-                     ['quota_set'])
+        quota_set = self.quotas_client.show_quota_set(
+            self.tenant_id)['quota_set']
         vcpus = int(quota_set['cores'])
         if vcpus == -1:
             raise self.skipException("default cores quota set is -1,"