Fixed wrong assertion in test_vmops.py

There is wrong assert method in
nova.tests.virt.vmwareapi.vmwareapi.test_vmops.py:640
while checking a number of calls mocked method 'mkdir'.

We should use assertEqual(3, len(mock_mkdir.mock_calls))
instead of self.assertTrue(3, len(mock_mkdir.mock_calls))

But number of calling method 'mkdir' not always is 3.
If dict block_device_info contains key 'block_device_mapping'
with any information, method 'mkdir' wouldn't be called in method
self._vmops.spawn(). That is why corresponding check been added.

Change-Id: Ifc26e112b9c2974e0fb7a91ba39d5b2d887bd549
Closes-Bug: #1335859
Remove redundant code in Libvirt driver

Change-Id: I98c5b5bb5a8710d32fadafe9781736a963616fec
Co-Authored-By: Thomas Kaergel <kaergel@b1-systems.de>
Correct exception for flavor extra spec create/update

When create/update flavor extra spec failed for v2 api, it will not
raise MetadataLimitExceeded for but two exceptions as following:
1) FlavorExtraSpecUpdateCreateFailed
2) FlavorNotFound

When create/update flavor extra spec failed for v3 api, it will not
raise DBDuplicateEntry but raise FlavorExtraSpecUpdateCreateFailed.

This patch updates the exception handling logic for create/update
flavor extra spec.

Change-Id: If3310a1cb44952e8fe2efe0b3358783f729bc190
Small grammar fix in libvirt/driver.py. fix all occurrences.

Change wording to be more descriptive/correct for greenthread.sleep()
Change-Id: I074391eaa7cfd580b89d89c2dd587796112c4a98
Merge "Small grammar fix in libvirt/driver.py. fix all occurrences."
Merge "Correct exception for flavor extra spec create/update"
Merge "Fixed wrong assertion in test_vmops.py"
Merge "Remove redundant code in Libvirt driver"