VMware: Unit test refactoring (image to vol - 2/2)
There are cases where a single test tests multiple methods. This
patch refactors the unit tests for the following methods in the
vmdk module to fix this issue:
* _create_virtual_disk_from_preallocated_image
* _create_virtual_disk_from_sparse_image
* _fetch_stream_optimized_image
There will be follow-up patches to fix the remaining unit tests.