tests/bios-tables-test: Sanitize test verbose output

tests/bios-tables-test: Sanitize test verbose output

Fix the extraneous extra blank lines in the test output when running with V=1.

Before:

    TEST: tests/bios-tables-test... (pid=25678)
      /i386/acpi/piix4:
    Looking for expected file 'tests/acpi-test-data/pc/DSDT'

    Using expected file 'tests/acpi-test-data/pc/DSDT'

    Looking for expected file 'tests/acpi-test-data/pc/FACP'

    Using expected file 'tests/acpi-test-data/pc/FACP'

    Looking for expected file 'tests/acpi-test-data/pc/APIC'

    Using expected file 'tests/acpi-test-data/pc/APIC'

    Looking for expected file 'tests/acpi-test-data/pc/HPET'

    Using expected file 'tests/acpi-test-data/pc/HPET'
    OK

After:

    TEST: tests/bios-tables-test... (pid=667)
      /i386/acpi/piix4:
    Looking for expected file 'tests/acpi-test-data/pc/DSDT'
    Using expected file 'tests/acpi-test-data/pc/DSDT'
    Looking for expected file 'tests/acpi-test-data/pc/FACP'
    Using expected file 'tests/acpi-test-data/pc/FACP'
    Looking for expected file 'tests/acpi-test-data/pc/APIC'
    Using expected file 'tests/acpi-test-data/pc/APIC'
    Looking for expected file 'tests/acpi-test-data/pc/HPET'
    Using expected file 'tests/acpi-test-data/pc/HPET'
    OK

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>