[BUGFIX] Failing test in autoloader with phpunit 3.6

The next phpunit extension will deliver phpunit 3.6. Some autoloader
unit tests fail with this version because of unclean tests. The patch
cleans that up to make the tests run with both phpunit 3.5 and 3.6.

Change-Id: Ib8cae2dfab5d9d638d481aa91b129f44fb0eaa01
Resolves: #35905
Releases: 6.0, 4.7, 4.6
Reviewed-on: http://review.typo3.org/10341
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn