[BUGFIX] Unused variable assigned twice in one function call

The refactoring of the Element Browser and Record List introduced
a second "unused" variable which is named the same. This is not
allowed in PHP7, thus resulting in a PHP error in the unit tests.

Releases: master
Resolves: #70535
Change-Id: Ibd96f11b190df6d00baecd9332af48db7bc70a13
Reviewed-on: http://review.typo3.org/43930


Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Alexander Opitz <opitz.alexander@googlemail.com>
Tested-by: Alexander Opitz <opitz.alexander@googlemail.com>