Improve CI ansible plays to pass ansible-lint

Change-Id: I150c8952aad7b6fdb1260b343c26a96fb2360bce

tests/post.yml

@@ -31,18 +31,20 @@
     - name: Download /etc/hosts file to executor
       synchronize:
         src: "/etc/hosts"
-        dest: "{{ zuul.executor.log_root }}/{{inventory_hostname }}/"
+        dest: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}/"
         mode: pull
       ignore_errors: yes
 
     - name: dump all iptables rules
       shell: "iptables-save > /tmp/logs/iptables"
+      args:
+        creates: /tmp/logs/iptables
       become: true
 
     - name: Download /tmp/logs file to executor
       synchronize:
         src: "/tmp/logs"
-        dest: "{{ zuul.executor.log_root }}/{{inventory_hostname }}/"
+        dest: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}/"
         mode: pull
         rsync_opts:
           - "--quiet"