REQ_F_LINK_TIMEOUT is a hint that to look for linked timeouts to cancel,
we're leaving it even when it's already fired. Hence don't care to clear
it in io_kill_linked_timeout(), it's safe and is called only once.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>