[FOLLOWUP][BUGFIX] l10n_state field is not created when installing an ext

Fix PHPdoc comments of return types.

Change-Id: I58686de41b135694305ca146590cba1c66ee6716
Resolves: #80271
Releases: master
Reviewed-on: https://review.typo3.org/52081


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>