Enforce log hints in neutron.services.loadbalancer

This change enforces log hints use and removes debug level log
translation, modifications are validated through a hacking rule and
the change respects loggging guidelines.

Validate that hacking rules apply to directories:
    - neutron/services/loadbalancer

Change-Id: I5f2a1a8861728399f3852fc9704eb160c35f7f8d
Partial-bug: #1320867
Merge "Enforce log hints in neutron.services.loadbalancer"