After the prepare side has been moved to the only I/O scheduler that
cares, do the same for the cleanup and the NULL initialization.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211126115817.2087431-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>