Fix generator bug in walk_resources
Fix generator bug in walk_resources

This modifies walk_resources' recursive call to behave like a generator
call.

Change-Id: If4bc03f2c76d16b8e376f2646a77418aff9de3ba
Addresses-Issue: Jira/AQUILON-4816
Reviewed-By: Amad Aslam <fb1d531fb3ff6aeb9cbe6abe9b12f0508c508206@morganstanley.com>

quattor/aquilon,quattor/aquilon,quattor/aquilon