Clean up some stuff found by Coverity.

* modules/aaa/mod_authz_core.c
  (check_provider_list): Remove redundant code.
* modules/aaa/mod_auth.h
  (AUTHZ_DEFAULT_PROVIDER): Remove redundant definition.

Submitted by: Max Bowsher <maxb apache.org>
Reviewed by: bnicholes, rooneg


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@390506 13f79535-47bb-0310-9956-ffa450edef68