Improve message of the teardown.sh
Improve message of the teardown.sh

Currently the teardown doesn't care about destroy other lxc
containers and destroys everything.
Same for logical volumes in the lxc volume group.

This tweaks the message to make it more clear.

Closes-Bug: #1518492

Change-Id: If8bbd9c8b6cea4d18ad982ee676e0480a88a1a4e

cfarquhar/openstack-ansible,git-harry/os-ansible-deployment,Logan2211/openstack-ansible,os-cloud/os-ansible-deployment,major/openstack-ansible,git-harry/os-ansible-deployment,weezer/openstack-ansible,major/os-ansible-deployment,BjoernT/os-ansible-deployment,yanyao/newton,openstack/openstack-ansible,bunchc/openstack-ansible,major/os-ansible-deployment,yanyao/newton,bunchc/openstack-ansible,jpmontez/openstack-ansible,open-switch/infra_openstack-ansible,cloudnull/os-ansible-deployment,BjoernT/os-ansible-deployment,mrda/openstack-ansible,git-harry/os-ansible-deployment,stackforge/os-ansible-deployment,yanyao/openstack-ansible,robb-romans/openstack-ansible,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,mancdaz/openstack-ansible,yanyao/openstack-ansible,cfarquhar/openstack-ansible,stackforge/os-ansible-deployment,major/openstack-ansible,open-switch/infra_openstack-ansible,mancdaz/openstack-ansible,weezer/openstack-ansible,os-cloud/os-ansible-deployment,mrda/openstack-ansible,robb-romans/openstack-ansible,BjoernT/openstack-ansible,jpmontez/os-ansible-deployment,jpmontez/os-ansible-deployment,BjoernT/openstack-ansible,open-switch/infra_openstack-ansible,jpmontez/openstack-ansible,jpmontez/openstack-ansible,yanyao/openstack-deployment-liberty,mrda/openstack-ansible,yanyao/openstack-deployment-liberty,jpmontez/os-ansible-deployment,cloudnull/os-ansible-deployment,openstack/openstack-ansible,yanyao/openstack-deployment-liberty