Fix invalid assert_has_calls
Fix invalid assert_has_calls

This is to fix the invalid assert_has_calls usage,
"assert_has_calls = " should be "assert_has_calls(".

Change-Id: Id094dd90efde09b9a835d4492f4a92b8f8ad296e

klmitch/nova,openstack/nova,klmitch/nova,klmitch/nova,openstack/nova,mahak/nova,mahak/nova,klmitch/nova,openstack/nova,mahak/nova