[BUGFIX] Fix notice in SearchController

Resolves: #97229
Releases: main, 11.5
Change-Id: I908102d0f4b5b3f3fe686f0ccdc60604669a8173
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74022


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Bartsch <bo@cedev.de>