Update README with the correct path of JSON results location.
Update README with the correct path of JSON results location.

Update the README file with the corrrect location where the
result JSON files were saved.

Change-Id: I68d22288642016b2eda6bb002f7377c49a226cf8

openstack/refstack-client,stackforge/refstack-client,stackforge/refstack-client,openstack/refstack-client