This reverts commit 6e9fdc92b77915d5c7ab8fea751f48378f8b0080.

1) This did not fixed the issue
2) Long sleeping work items can cause IO requests to take as long as
   the longest work item
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>