Fix new node detection
Fix new node detection

For the openshift-node service, the new_node detection was checking for
stdout instead of rc causing it to always tag nodes as new. This commit
fixes it.

Change-Id: I518f386395b515f59e98877274f4a0fce52ec4d5
Closes-Bug: #1802323

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates