MNAIO: Ensure the aria log path exists

If the log path doesn't exist, we should create it - otherwise
the download command will fail because it cannot create the log.

Change-Id: I8f3d7604da11aae89c83ec3bd5c28b05f9853324

multi-node-aio/playbooks/download-vms.yml

@@ -37,7 +37,8 @@
         return_content: yes
       register: _manifest_file
 
-    - set_fact:
+    - name: Register manifest content as a fact
+      set_fact:
         _manifest_content: "{{ _manifest_file.content | from_json }}"
 
     - name: Install aria download manager
@@ -55,6 +56,11 @@
           {% endfor %}
         dest: "/tmp/aria2c.input"
 
+    - name: Ensure that the aria log file path exists
+      file:
+        path: "{{ aria2c_log_path }}"
+        state: directory
+
     - name: Download artifacts
       command: >-
         aria2c