blockdev: Remove 'media' parameter from blockdev_init() The remaining users shouldn't be there with blockdev-add and are easy to move to drive_init(). Bonus bug fix: As a side effect, CD-ROM drives can now use block drivers on the read-only whitelist without explicitly specifying read-only=on, even if a format is explicitly specified. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>