For consistency with the rest of pblk, use rqd->end_io to point to the
function taking care of ending the request on the completion path.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>