[CLEANUP] #5203 Shorten the boolean casts

Change-Id: Ice72bff908bdea2093a92ef7f75ec8495db44443
Reviewed-on: http://review.typo3.org/35438
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>