block/blkio: Make driver nvme-io_uring take a "path" instead of a "filename"

block/blkio: Make driver nvme-io_uring take a "path" instead of a "filename"

The nvme-io_uring driver expects a character special file such as
/dev/ng0n1. Follow the convention of having a "filename" option when a
regular file is expected, and a "path" option otherwise.

This makes io_uring the only libblkio-based driver with a "filename"
option, as it accepts a regular file (even though it can also take a
block special file).

Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-id: 20221028233854.839933-1-afaria@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>