Revert "[BUGFIX] Memory consumption in DataHandler->processClearCacheQueue"

This reverts commit 31518c96e9c705a91898cce009d7f47be238bce7.

Change-Id: I64053da1d04716679c9e7227a9d6885ccd047fdb
Reviewed-on: http://review.typo3.org/35221
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Oliver Hader <oliver.hader@typo3.org>