pidl/ws: fix missing $name when generating MAPI dissector

pidl/ws: fix missing $name when generating MAPI dissector

Port Wireshark commit 0e80176

Author: Alexis La Goutte <alexis.lagoutte@gmail.com>
Date:   Fri Mar 4 19:28:26 2016 +0100

    PIDL (NDR): fix missing $name when regenerate MAPI dissector

    Issue coming from ge41f08858b

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Mon Jun 20 16:20:00 CEST 2016 on sn-devel-144