Avoid excessive sleep in vmware unit test

The patch Id6e2be2b407eb08e269c35e0f89d235c67a1ab99 added a retry
decorator on create_vm in vmware driver. Such decorator makes the
negative unit test do excessive sleeps and retries. The test eventually
stopped by the test executor with a Timeout exception but the test was
modified to assert that as a success. This makes the test pass after
160 seconds.

This patch mocks the sleep behind the retry decorator to make the test
fast and reverts the assert in the test.

Change-Id: I7c7e698bf559b69a2f09402c265e6e387c3b077a
Related-Bug: #1908408

nova/tests/unit/virt/vmwareapi/test_vm_util.py

@@ -15,9 +15,9 @@
 #    under the License.
 
 import collections
-import fixtures
 
 import mock
+from oslo_service import fixture as oslo_svc_fixture
 from oslo_utils import units
 from oslo_utils import uuidutils
 from oslo_vmware import exceptions as vexc
@@ -1024,6 +1024,8 @@ class VMwareVMUtilTestCase(test.NoDBTestCase):
         """Ensure we warn when create_vm() fails after we passed an
         unrecognised guestId
         """
+        # avoid real sleeps during test due to te retry decorator on create_vm
+        self.useFixture(oslo_svc_fixture.SleepFixture())
 
         found = [False]
 
@@ -1042,8 +1044,7 @@ class VMwareVMUtilTestCase(test.NoDBTestCase):
             vm_util.ExtraSpecs(),
             os_type='invalid_os_type')
 
-        # Because of retries timeout will be raised
-        self.assertRaises(fixtures.TimeoutException,
+        self.assertRaises(vexc.VMwareDriverException,
                           vm_util.create_vm, session, self._instance,
                           'folder', config_spec, 'res-pool')
         self.assertTrue(found[0])