t/test.sh: work around NetBSD setting -A for 'ls' when root (again).

Apply the same workaround for the "compression9" tests that was
applied in commit 51bd5832b391f4c128cc42a3a5970733775f1ba7.

Signed-off-by: Zoran Zaric <zz@zoranzaric.de>
Reviewed-by: Rob Browning <rlb@defaultvalue.org>