s3:client: Fix a use-after-free issue in smbclient

s3:client: Fix a use-after-free issue in smbclient

Detected by

    make test TESTS="samba3.blackbox.chdir-cache"

with an optimized build or with AddressSanitizer.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15268

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
(cherry picked from commit 9c707b4be27e2a6f79886d3ec8b5066c922b99bd)

Autobuild-User(v4-16-test): Jule Anger <janger@samba.org>
Autobuild-Date(v4-16-test): Tue Jan  3 19:19:57 UTC 2023 on sn-devel-184