[TASK] Fix tests for DirectoryNodeTest

The tests have not been adjusted when
http://forge.typo3.org/issues/52668
was merged.

Resolves: #57055
Releases: 6.2
Change-Id: I259c7b5462d372f3244ee4c2e89a96cef0780478
Reviewed-on: https://review.typo3.org/28513
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn