Address Ansible bare variable usage

When executing the role with Ansible 2.1, the following
deprecation warning is issued in the output for some tasks.

[DEPRECATION WARNING]: Using bare variables is deprecated.

This patch addresses the tasks to fix the behaviour appropriately.

The patch also addresses removing the use of with_items if the
list only contains a single item.

Change-Id: I8326d53d3a57fd84a55febc21f6ae1a64fced415

tasks/lxc_cache_preparation.yml

@@ -74,7 +74,7 @@
     regexp: "{{ item.regexp }}"
     line: "{{ item.line }}"
     state: present
-  with_items: lxc_cache_sshd_configuration
+  with_items: "{{ lxc_cache_sshd_configuration }}"
   tags:
     - lxc-cache
     - lxc-cache-update

tasks/lxc_install.yml

@@ -34,6 +34,6 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: lxc_pip_packages
+  with_items: "{{ lxc_pip_packages }}"
   tags:
     - lxc-pip-packages

tasks/lxc_install_apt.yml

@@ -38,7 +38,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: lxc_packages
+  with_items: "{{ lxc_packages }}"
   tags:
     - lxc-apt-packages
 

tasks/lxc_install_yum.yml

@@ -21,18 +21,16 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: lxc_packages
+  with_items: "{{ lxc_packages }}"
   tags:
     - lxc-packages
 
 - name: Create base directories
   file:
-    path: "{{ item }}"
+    path: "/opt/lxc_embedded"
     state: "directory"
     owner: "root"
     group: "root"
-  with_items:
-    - /opt/lxc_embedded
   tags:
     - lxc-directories
 
@@ -118,12 +116,10 @@
 
 - name: Remove sub system lock if found
   file:
-    path: "{{ item }}"
+    path: "/var/lock/subsys/lxc"
     state: "absent"
     owner: "root"
     group: "root"
-  with_items:
-    - /var/lock/subsys/lxc
   tags:
     - lxc-directories
 

tasks/lxc_kernel_tuning.yml

@@ -21,4 +21,4 @@
     state: "{{ item.state|default('present') }}"
     reload: "{{ item.reload|default('yes') }}"
   ignore_errors: true
-  with_items: lxc_kernel_options
+  with_items: "{{ lxc_kernel_options }}"