examples/winexe: fix fetching return code of the remote command

examples/winexe: fix fetching return code of the remote command

ctrl_inbuf field is used to parse remote-side information. A typo was
there that tried to parse return code as "version 0x%x" whereas the
correct way to do it (tested on Windows 10) is to scan for "return_code
%x".

Signed-off-by: Yury Lunev <yury.lunev@gmail.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Jul 28 18:01:16 UTC 2022 on sn-devel-184