Fix etcd-upgrade sanity checks

This commit ensures that only oo_etcd_to_config and
oo_masters_to_config are checked during sanity_checks.

This will prevent hosts that have not had facts gathered
(such as nodes) will not be processed for correct inventory
and runtime facts.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1536317

playbooks/openshift-etcd/upgrade.yml

@@ -3,5 +3,6 @@
   vars:
     skip_verison: True
     l_init_fact_hosts: "oo_masters_to_config:oo_etcd_to_config:oo_lb_to_config"
+    l_sanity_check_hosts: "{{ groups['oo_etcd_to_config'] | union(groups['oo_masters_to_config']) }}"
 
 - import_playbook: private/upgrade_main.yml