GNU: Use overrides' instead of __overrides' for the argument itself.

svn path=/nixpkgs/trunk/; revision=33585

pkgs/os-specific/gnu/default.nix

@@ -4,13 +4,13 @@ args@{ fetchgit, stdenv, autoconf, automake, automake111x, libtool
 , texinfo, glibcCross, hurdPartedCross, libuuid, samba_light
 , gccCrossStageStatic, gccCrossStageFinal
 , forceBuildDrv, forceSystem, callPackage, platform, config, crossSystem
-, __overrides ? {} }:
+, overrides ? {} }:
 
 with args;
 
 rec {
   # Allow callers to override elements of this attribute set.
-  inherit __overrides;
+  __overrides = overrides;
 
   hurdCross = forceBuildDrv(import ./hurd {
     inherit fetchgit stdenv autoconf libtool texinfo machHeaders