After commit 64c7f1d1, we went from 1 to 2 holes in my
test setup. If we move the timeout field a bit, we remove
both of those holes and shrink struct request by 8 bytes.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>