bots: Adjust atomic.setup for latest Fedora 27 Atomic
bots: Adjust atomic.setup for latest Fedora 27 Atomic

The latest image now configures the default
/etc/sysconfig/docker-storage-setup to put docker images into the root
LV instead of creating a separate docker LV.  So check if
atomicos/docker-root-lv actually exists before trying to resize it.

Fixes #8691

mvollmer/cockpit,mvollmer/cockpit,cockpituous/cockpit,mvollmer/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,deryni/cockpit,stefwalter/cockpit,deryni/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,andreasn/cockpit,deryni/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,cockpit-project/cockpit,mareklibra/cockpit,andreasn/cockpit,martinpitt/cockpit,garrett/cockpit,stefwalter/cockpit,mvollmer/cockpit,martinpitt/cockpit,garrett/cockpit,deryni/cockpit,moraleslazaro/cockpit,andreasn/cockpit,cockpit-project/cockpit,mareklibra/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,cockpituous/cockpit,stefwalter/cockpit,mareklibra/cockpit,stefwalter/cockpit,mareklibra/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,deryni/cockpit,moraleslazaro/cockpit,garrett/cockpit,martinpitt/cockpit,mareklibra/cockpit,andreasn/cockpit,garrett/cockpit,martinpitt/cockpit,stefwalter/cockpit,deryni/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,garrett/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,deryni/cockpit,cockpituous/cockpit