attached-openstack-volume will fail if the xfs filesystem has been craeted but is not mounted

[colin-nolan]

If the filesystem is xfs, the "create filesystems on logical volumes" step will fail if the fs has been created but is not mounted.

An existing xfs fs must be mounted if resizefs is set, as per the requirements of the filesystem module: http://docs.ansible.com/ansible/filesystem_module.html.