fix internal var name

tasks/install.yml

@@ -30,11 +30,11 @@
   - name: Check if database is initialized
     stat:
       path: "{{ postgres_data_dir }}/PG_VERSION"
-    register: pgdata_dir_version
+    register: __pgdata_dir_version
 
   - name: Ensure database is initialized
     command: "/usr/pgsql-{{ __postgres_version }}/bin/postgresql-{{ __postgres_version }}-setup initdb"
-    when: not pgdata_dir_version.stat.exists
+    when: not __pgdata_dir_version.stat.exists
     become: true
     become_user: "{{ postgres_user }}"
   become: True