bin/55612: libarchive tests pollute /tmp w/o cleanup

[martin%NetBSD.org@localhost]

>Number:         55612
>Category:       bin
>Synopsis:       libarchive tests pollute /tmp w/o cleanup
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Aug 28 16:55:00 +0000 2020
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.71
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD h-pulse.aprisoft.de 9.99.71 NetBSD 9.99.71 (GENERIC64) #154: Fri Aug 28 10:38:10 CEST 2020 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/evbarm/compile/GENERIC64 evbarm
Architecture: aarch64
Machine: evbarm
>Description:

Running the /usr/tests/lib/libarchive tests pollutes /tmp and does not clean
up. Tests are not supposed to make changes anywhere outside the temporary
ATF directory, and also are expected to clean up fully.

>How-To-Repeat:

ls -l /tmp; cd /usr/tests/lib/libarchive && atf-run; ls -l /tmp

>Fix:
Set TMPDIR to . during the test?