tests/functional: honour self.workdir in ACPI bits tests

tests/functional: honour self.workdir in ACPI bits tests

The ACPI bits test sets up its own private temporary directory into it
creates scratch files. This is justified by a suggestion that we need
to be able to preserve the scratch files. We have the ability to
preserve the scratch dir with our functional harness, so there's no
reason to diverge from standard practice in file placement.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20241121154218.1423005-9-berrange@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20241121165806.476008-9-alex.bennee@linaro.org>