Remove unused class variables

cls.binary in ServicesAdminNegativeV253TestJSON is not used, so
this is to remove it. Besides, cls.services in
VolumeServicesNegativeTest need not be a class variable.

Change-Id: If3fcb53ff0ee5e2c608d1a675fb18600ef39dd2e
diff --git a/tempest/api/compute/admin/test_services_negative.py b/tempest/api/compute/admin/test_services_negative.py
index 993c8ec..d264829 100644
--- a/tempest/api/compute/admin/test_services_negative.py
+++ b/tempest/api/compute/admin/test_services_negative.py
@@ -74,8 +74,6 @@
     @classmethod
     def resource_setup(cls):
         super(ServicesAdminNegativeV253TestJSON, cls).resource_setup()
-        # Nova returns 400 if `binary` is not nova-compute.
-        cls.binary = 'nova-compute'
         cls.fake_service_id = data_utils.rand_uuid()
 
     @decorators.attr(type=['negative'])
diff --git a/tempest/api/volume/admin/test_volume_services_negative.py b/tempest/api/volume/admin/test_volume_services_negative.py
index 6f3dbc6..3a863a1 100644
--- a/tempest/api/volume/admin/test_volume_services_negative.py
+++ b/tempest/api/volume/admin/test_volume_services_negative.py
@@ -23,10 +23,9 @@
     @classmethod
     def resource_setup(cls):
         super(VolumeServicesNegativeTest, cls).resource_setup()
-        cls.services = cls.admin_volume_services_client.list_services()[
-            'services']
-        cls.host = cls.services[0]['host']
-        cls.binary = cls.services[0]['binary']
+        services = cls.admin_volume_services_client.list_services()['services']
+        cls.host = services[0]['host']
+        cls.binary = services[0]['binary']
 
     @decorators.attr(type='negative')
     @decorators.idempotent_id('3246ce65-ba70-4159-aa3b-082c28e4b484')