io_uring: don't cancel-track common timeouts

Don't account usual timeouts (i.e. not linked) as REQ_F_INFLIGHT but
keep behaviour prior to dd59a3d5

 ("io_uring: reliably cancel linked
timeouts").

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/104441ef5d97e3932113d44501fda0df88656b83.1616696997.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>