iotests: Make 089 compatible with compat=0.10

The only thing that is missing is a _filter_img_info after the
"$QEMU_IO -c info" invocations.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171123020832.8165-15-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>