io_uring: delete misleading comment in io_fill_cqe_aux()

io_fill_cqe_aux() doesn't overflow completions, however it might fail
them and lets the caller handle it. Remove the comment, which doesn't
make any sense.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/021aa8c1d8f20ef2b66da6aeabb6b511938fd2c5.1745843119.git.asml.silence@gmail.com


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