s3:winbindd fix use of uninitialized variables

Bug: https://bugzilla.samba.org/show_bug.cgi?id=10280

Signed-off-by: Christian Ambach <ambi@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit 7393781a57891687b464762b0954e6c936f750bb)

Autobuild-User(v4-1-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-1-test): Thu Jan  2 21:49:28 CET 2014 on sn-devel-104