To fix test_get_dss_rp in test_vmware_vmdk.py

The test "test_get_dss_rp" in test_vmware_vmdk.py is not testing
the positive case as intended. Rather, it tests the negative case
(no datastores) which is already covered by
"test_get_dss_rp_without_datastores".

Change-Id: I5b4802e22218217e0338fc721fc0ce1efeaee4f1
Closes-Bug: #1251126
Remove dead code from test_get_volume_stats()

The _emulate_vgs_execute() routine is never called because the function
that calls it (get_all_volume_groups) is overridden to return fake
output without executing vgs.

Change-Id: I3d3f536f7d85128547dc9e758e3930412ebed121
Merge "Remove dead code from test_get_volume_stats()"
Merge "To fix test_get_dss_rp in test_vmware_vmdk.py"