In test_agent.py change variable names from 'mocked_' to 'mock_' to
follow convention we use in openstack/ironic.
Change the mock variable names 'wsgi_server_cls' and
'mocked_server_maker' in some of the unit tests to
'mock_make_server'. It is the convention to have 'mock' in the
variable names for mock objects.
Not changing the other unit test files at this time.
Change-Id: I844071c928f92778e8ce0bfbdb8fb89fc26ee43b