io_uring: remove excessive unlikely on IS_ERR

The IS_ERR function uses the IS_ERR_VALUE macro under the hood which
already wraps the condition into unlikely.

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Link: https://lore.kernel.org/r/20230109185854.25698-1-dmitrii.bundin.a@gmail.com


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