Fixes misuse of assertTrue in virt test scripts

Misuse of assertTrue in places where assertEqual should be used.

If assertTrue is used, the test will always pass
if the first argument's boolean cast is True.
The second argument passed to assertTrue() will be regarded
as the error message when the assertion fails.

Fixes bug #1220541

Change-Id: I63ec4f35ee1a2430a5f6b54e40108b2c4ce3d480
Merge "Fixes misuse of assertTrue in virt test scripts"