update linode role to work with CentOS

roles/linode/tasks/main.yml

@@ -10,6 +10,8 @@
     name: cockpit.socket
     state: stopped
     enabled: no
+  when:
+    - ansible_os_family == 'Fedora'
 
 - name: Close cockpit port
   firewalld:
@@ -18,11 +20,15 @@
     state: disabled
     permanent: yes
     immediate: yes
+  when:
+    - ansible_os_family == 'Fedora'
 
 - name: Remove cockpit motd banner
   file:
     path: /etc/motd.d/cockpit
     state: absent
+  when:
+    - ansible_os_family == 'Fedora'
 
 - name: Install fail2ban
   dnf: