winbindd: Route predefined domains through the BUILTIN domain child

winbindd: Route predefined domains through the BUILTIN domain child

Without this eg "NT Authority" didn't work:

  $ bin/wbinfo -n "NT Authority/Authenticated Users"
  failed to call wbcLookupName: WBC_ERR_DOMAIN_NOT_FOUND
  Could not lookup name NT Authority/Authenticated Users

  $ bin/wbinfo --group-info="NT Authority/Authenticated Users"
  failed to call wbcGetgrnam: WBC_ERR_DOMAIN_NOT_FOUND
  Could not get info for group NT Authority/Authenticated Users

With the patch:

  $ bin/wbinfo -n "NT Authority/Authenticated Users"
  S-1-5-11 SID_WKN_GROUP (5)

  $ bin/wbinfo --group-info="NT Authority/Authenticated Users"
  NT AUTHORITY\authenticated users:x:10002:

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12164

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: David Mulder <dmulder@suse.com>
Reviewed-by: Andreas Schneider <asn@samba.org>
Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Wed Dec  5 11:27:22 CET 2018 on sn-devel-144