Fix scaleup failure for hostname override

This commit ensures scaleup and new install plays
fail if specifying openshift_kubelet_name_override in
inventory.

(cherry picked from commit 37a7af4a131a9d3a46f57d1315ce313641eaff5e)

playbooks/prerequisites.yml

@@ -1,7 +1,7 @@
 ---
 # l_scale_up_hosts may be passed in via various scaleup plays.
 - name: Fail openshift_kubelet_name_override for new hosts
-  hosts: "{{ l_scale_up_hosts | default('oo_nodes_to_config') }}"
+  hosts: "{{ l_scale_up_hosts | default('nodes') }}"
   tasks:
   - name: Fail when openshift_kubelet_name_override is defined
     fail: