Avoid KeyError: 'CONFIG_CINDER_VOLUMES_SIZE' error
Avoid KeyError: 'CONFIG_CINDER_VOLUMES_SIZE' error

- When CONFIG_CINDER_VOLUMES_CREATE=n, it should always pass in the cinder
  volume size calculation block.

Change-Id: I6cf6fd4767c66dc87ea31cbafe17bb8fcfebbf70
Fixes: rhbz#1164359
Signed-off-by: Gael Chamoulaud <68646863a1a9108d0246eb96cb6356f9fa9a34f3@redhat.com>

mahak/packstack,mahak/packstack,mahak/packstack,xbezdick/packstack,stackforge/packstack,imcsk8/packstack,xbezdick/packstack,openstack/packstack,fr34k8/packstack,fr34k8/packstack,openstack/packstack,openstack/packstack,xbezdick/packstack,imcsk8/packstack,palmer159/openstack-test,palmer159/openstack-test,palmer159/openstack-test,stackforge/packstack,stackforge/packstack,fr34k8/packstack,imcsk8/packstack