Follow up changes to granular placement policy reviews

This is just a consolidated patch for minor issues found
during the granular placement policy series.

Part of blueprint granular-placement-policy

Change-Id: I8f5d3ed143aa88bacf9e9f39df224b314688b412

nova/api/openstack/placement/context.py

@@ -36,8 +36,8 @@ class RequestContext(context.RequestContext):
                 {'project_id': self.project_id, 'user_id': self.user_id}
         :param fatal: if False, will return False when an
             exception.PolicyNotAuthorized occurs.
-        :raises nova.exception.PolicyNotAuthorized: if verification fails and
-            fatal is True.
+        :raises nova.api.openstack.placement.exception.PolicyNotAuthorized:
+            if verification fails and fatal is True.
         :return: returns a non-False value (not necessarily "True") if
             authorized and False if not authorized and fatal is False.
         """

nova/api/openstack/placement/policy.py

@@ -52,6 +52,8 @@ def get_enforcer():
     # This method is used by oslopolicy CLI scripts in order to generate policy
     # files from overrides on disk and defaults in code. We can just pass an
     # empty list and let oslo do the config lifting for us.
+    # TODO(mriedem): Change the project kwarg value to "placement" once
+    # this code is extracted from nova.
     cfg.CONF([], project='nova')
     init()
     return _ENFORCER_PLACEMENT