Add become for fluentd create config directory task

Become option is missed in patch #398682, this patchset fix this issue.

Change-Id: I228c31486210ef1de76601d3ea4ee955a628ca73
Partial-Implements: blueprint ansible-specific-task-become

ansible/roles/common/tasks/config.yml

@@ -15,6 +15,7 @@
     path: "{{ node_config_directory }}/{{ item }}"
     state: "directory"
     recurse: yes
+  become: true
   with_items:
     - "fluentd"
     - "fluentd/input"