style: make ansible-lint happy

roles/rsyslog/tasks/main.yml

@@ -26,5 +26,5 @@
     state: present
     insertbefore: '^# --- BEGIN PVE ---$'
     line: "{{ item.address }}		{{ item.name }}"
-  loop: "{{ pretty_named_hosts }}"
+  loop: "{{ rsyslog_pretty_named_hosts }}"
   notify: Restart rsyslog

roles/rsyslog/vars/main.yml

@@ -1,6 +1,6 @@
 ---
 
-pretty_named_hosts:
+rsyslog_pretty_named_hosts:
   - name: enbarr
     address: 10.233.212.50
   - name: garreg-mach