A friendly way to setup an io_uring, with default linux.io_uring_params. entries
must be a power of two between 1 and 4096, although the kernel will make the final call on how many entries the submission and completion queues will ultimately have, see https://github.com/torvalds/linux/blob/v5.8/fs/io_uring.c#L8027-L8050. Matches the interface of io_uring_queue_init() in liburing.