Remove unused session variable in test setup

Change-Id: Ib53a0d76d660cc7a002894ef63bc25c293f92fa0

nova/tests/test_instance_types.py

@@ -33,10 +33,6 @@ LOG = logging.getLogger(__name__)
 
 class InstanceTypeTestCase(test.TestCase):
     """Test cases for instance type code"""
-    def setUp(self):
-        super(InstanceTypeTestCase, self).setUp()
-        session = get_session()
-
     def _generate_name(self):
         """return a name not in the DB"""
         nonexistent_flavor = str(int(time.time()))