[TASK] Adapt FAL unit tests to new vfsStream version

The new phpunit extension ships with a vfsStream version
that changed the create methods parameters. Therefore all
vfsStream dependent unit tests fail.

Change-Id: I573535ac067c782f5c100f062406efc3201f64c2
Resolves: #36687
Releases: 6.0
Reviewed-on: http://review.typo3.org/10842
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn