ACPICA: Update ACPI_IS_DEBUG_ENABLED macro.

Add extra parens to allow use of !ACPI_IS_DEBUG_ENABLED.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>