[TASK] Remove unused property $fileProcessor

In PageFunctionsController a property $fileProcessor is
defined but unused.

Resolves: #61456
Releases: 6.3
Change-Id: I7f19c533ab3f906da414d184e6730d9eed836d49
Reviewed-on: http://review.typo3.org/32657
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>