[CLEANUP] #5203 Shorten the boolean casts

Change-Id: I99c4297a75be45c30e0dcd839931fb5e9a9e1d29
Reviewed-on: http://review.typo3.org/35439
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>