[CLEANUP] Fix some CGL violations in ext_tables.php

* comment line length
* intentions

Resolves: #58241
Releases: 6.2
Change-Id: I15afac656a0220826ec9d4d6d6e4c84024a20c3b
Reviewed-on: https://review.typo3.org/29680
Reviewed-by: Nico de Haen
Tested-by: Nico de Haen