Default nova_cinder_rbd_inuse when it is not set
Default nova_cinder_rbd_inuse when it is not set

If the fact is not set, default it according to the os_nova role
defaults.

Change-Id: I368594c920953a8e042329aabb927386d2f0788a

stackforge/os-ansible-deployment,openstack/openstack-ansible,stackforge/os-ansible-deployment,openstack/openstack-ansible