[CLEANUP] #5203 Shorten the boolean casts

Change-Id: I9baac9775bd5822d2ab0393babd89a58b9b6e10c
Reviewed-on: http://review.typo3.org/35440
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>