io_uring: remove redundant req_set_fail()

req_set_fail() in io_submit_sqe() is redundant, remove it.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20210827094609.36052-2-haoxu@linux.alibaba.com


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