Description of problem:
The validators: "Undercloud Neutron Sanity Check" fail with "MODULE FAILURE" error.


Version-Release number of selected component (if applicable):
openstack-tripleo-validations-9.3.1-0.20181008110754.4064fb7.el7ost.noarch

How reproducible:
100%

Steps to Reproduce:
1. Install OSP14 (from 2018-12-03.2)
2. Go to UI
3. Run the validator "Undercloud Neutron Sanity Chec"

Actual results:
The validator should passes/fails with clear message.

Expected results:
Task 'Run neutron-sanity-check' failed:
Host: undercloud
Message: MODULE FAILURE

stderr:
    Traceback (most recent call last):
      File "/tmp/ansible_cw1XRq/ansible_module_neutron_sanity_check.py", line 100, in <module>
        main()
      File "/tmp/ansible_cw1XRq/ansible_module_neutron_sanity_check.py", line 79, in main
        stderr=subprocess.PIPE)
      File "/usr/lib64/python2.7/subprocess.py", line 711, in __init__
        errread, errwrite)
      File "/usr/lib64/python2.7/subprocess.py", line 1327, in _execute_child
        raise child_exception
    OSError: [Errno 2] No such file or directory

Failure! The validation failed for all hosts:
* undercloud

Additional info:
Also from CLI the validator fails with the same error:

(undercloud) [stack@undercloud-0 ~]$  ansible-playbook -i /usr/bin/tripleo-ansible-inventory /usr/share/openstack-tripleo-validations/validations/undercloud-neutron-sanity-check.yaml 

PLAY [undercloud] *************************************************************************************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************************************************************************************
ok: [undercloud]

TASK [Run neutron-sanity-check] ***********************************************************************************************************************************************************************************
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: OSError: [Errno 2] No such file or directory
fatal: [undercloud]: FAILED! => {"changed": false, "module_stderr": "Traceback (most recent call last):\n  File \"/tmp/ansible_kW8jBX/ansible_module_neutron_sanity_check.py\", line 100, in <module>\n    main()\n  File \"/tmp/ansible_kW8jBX/ansible_module_neutron_sanity_check.py\", line 79, in main\n    stderr=subprocess.PIPE)\n  File \"/usr/lib64/python2.7/subprocess.py\", line 711, in __init__\n    errread, errwrite)\n  File \"/usr/lib64/python2.7/subprocess.py\", line 1327, in _execute_child\n    raise child_exception\nOSError: [Errno 2] No such file or directory\n", "module_stdout": "", "msg": "MODULE FAILURE", "rc": 1}
 [WARNING]: Could not create retry file '/usr/share/openstack-tripleo-validations/validations/undercloud-neutron-sanity-check.retry'.         [Errno 13] Permission denied: u'/usr/share/openstack-tripleo-
validations/validations/undercloud-neutron-sanity-check.retry'


PLAY RECAP ********************************************************************************************************************************************************************************************************
undercloud                 : ok=1    changed=0    unreachable=0    failed=1