Fix ansible linting issues

These issues can show up when we'll bump ansible lint to a more
recent version.

Change-Id: Ic8fcc374543419dbc7e299040e293fb78bc932fc

handlers/main.yml

@@ -33,7 +33,9 @@
     state: "reloaded"
 
 - name: Restart machined
-  command: "systemctl restart systemd-machined.service"
+  systemd:
+    name: "systemd-machined.service"
+    state: "restarted"
 
 - name: Restart irqbalance
   service:

tasks/lxc_cache_preparation.yml

@@ -17,6 +17,9 @@
   command: "systemctl --version"
   changed_when: false
   register: systemd_version
+  tags:
+    # Avoid ANSIBLE0006 lint issue: systemctl used in place of systemd module
+    - skip_ansible_lint
 
 - block:
     - name: Create machined proxy override unit directories