io_uring: rename io_get_cqring

Rename io_get_cqring() into io_get_cqe() for consistency with SQ, and
just because the old name is not as clear.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a46a53e3f781de372f5632c184e61546b86515ce.1621201931.git.asml.silence@gmail.com


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