[BUGFIX] Fix warning in NewContentElementController

Resolves: #95778
Releases: master
Change-Id: I764dc299cb192e4ebbcb00b21553f474355c55cb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71976


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>