Remove unused client in setup_clients

This is to remove unused client in setup_clients
to keep code clean.

Change-Id: I822fddd46f7ac2ee06125c3588830eb1127b355a
diff --git a/tempest/api/compute/admin/test_migrations.py b/tempest/api/compute/admin/test_migrations.py
index aa75348..18655cb 100644
--- a/tempest/api/compute/admin/test_migrations.py
+++ b/tempest/api/compute/admin/test_migrations.py
@@ -30,7 +30,6 @@
     def setup_clients(cls):
         super(MigrationsAdminTest, cls).setup_clients()
         cls.client = cls.os_adm.migrations_client
-        cls.flavors_admin_client = cls.os_adm.flavors_client
 
     @decorators.idempotent_id('75c0b83d-72a0-4cf8-a153-631e83e7d53f')
     def test_list_migrations(self):
@@ -54,8 +53,8 @@
 
     def _flavor_clean_up(self, flavor_id):
         try:
-            self.flavors_admin_client.delete_flavor(flavor_id)
-            self.flavors_admin_client.wait_for_resource_deletion(flavor_id)
+            self.admin_flavors_client.delete_flavor(flavor_id)
+            self.admin_flavors_client.wait_for_resource_deletion(flavor_id)
         except exceptions.NotFound:
             pass
 
@@ -68,9 +67,9 @@
 
         # First we have to create a flavor that we can delete so make a copy
         # of the normal flavor from which we'd create a server.
-        flavor = self.flavors_admin_client.show_flavor(
+        flavor = self.admin_flavors_client.show_flavor(
             self.flavor_ref)['flavor']
-        flavor = self.flavors_admin_client.create_flavor(
+        flavor = self.admin_flavors_client.create_flavor(
             name=data_utils.rand_name('test_resize_flavor_'),
             ram=flavor['ram'],
             disk=flavor['disk'],
diff --git a/tempest/api/compute/admin/test_servers_negative.py b/tempest/api/compute/admin/test_servers_negative.py
index 13a411b..adb49a5 100644
--- a/tempest/api/compute/admin/test_servers_negative.py
+++ b/tempest/api/compute/admin/test_servers_negative.py
@@ -34,7 +34,6 @@
         super(ServersAdminNegativeTestJSON, cls).setup_clients()
         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
diff --git a/tempest/api/compute/servers/test_create_server.py b/tempest/api/compute/servers/test_create_server.py
index 20646d1..fd5e50e 100644
--- a/tempest/api/compute/servers/test_create_server.py
+++ b/tempest/api/compute/servers/test_create_server.py
@@ -236,7 +236,6 @@
     @classmethod
     def setup_clients(cls):
         super(ServersWithSpecificFlavorTestJSON, cls).setup_clients()
-        cls.flavor_client = cls.os_adm.flavors_client
         cls.client = cls.servers_client
 
     @classmethod