Make Samba-specific HDB auth status API a wrapper on the existing auditing API,
with a view towards unifying the two APIs in a future commit.
The term "auth status" is replaced with "auth event", and the HDB auth_status
method is replaced with a more general purpose audit method which has access to
the entire request structure.
We're logging SUCCESS even when the KDC sends error replies. That's
because we're returning success to process_request() even when we send
errors to clients. The error we want to send to the client, and that we
succeed or fail to send it, are different statuses.
To fix this we'll add a `ret` field to the common service request state
structure, HEIM_SVC_REQUEST_DESC_COMMON_ELEMENTS /
heim_svc_req_desc_common_s.
