BlockBackend's name space is separate only to keep the initial patches
simple. Time to merge the two.
Retain bdrv_find() and bdrv_get_device_name() for now, to keep this
series manageable.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>