Use first_master_client_binary from hostvars[groups.oo_first_master.0]

Since first_master_client_binary is initialized in oo_first_master, it
should be collected from oo_first_master.0. This patch changes to use
first_master_client_binary from hostvars[groups.oo_first_master.0] on
GlusterFS cluster health task.

roles/openshift_storage_glusterfs/tasks/cluster_health.yml

@@ -3,7 +3,7 @@
 # lib_utils/library/glusterfs_check_containerized.py
 - name: Check for GlusterFS cluster health
   glusterfs_check_containerized:
-    oc_bin: "{{ first_master_client_binary }}"
+    oc_bin: "{{ hostvars[groups.oo_first_master.0]['first_master_client_binary'] }}"
     oc_conf: "{{ openshift.common.config_base }}/master/admin.kubeconfig"
     oc_namespace: "{{ glusterfs_namespace }}"
     cluster_name: "{{ glusterfs_name }}"