libsmb: Fix directory listing against old servers

libsmb: Fix directory listing against old servers

cli_list_trans_recv() can be called multiple times. When it's done, it
return NT_STATUS_OK and set *finfo to NULL. cli_list_old_recv() did
not do the NULL part, so smbclient would endlessly loop.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=15382

Signed-off-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 Jun  1 21:54:42 UTC 2023 on atb-devel-224