block/blkio: move blkio_connect() in the drivers functions

This is in preparation for the next patch, where for virtio-blk
drivers we need to handle the failure of blkio_connect().

Let's also rename the *_open() functions to *_connect() to make
the code reflect the changes applied.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20230727161020.84213-2-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
1 file changed