ACPI / LPSS: make code less confusing for reader

The excerpt like this:

	if (err) {
		err = 0;
		goto error_out;
	}

makes a reader confused even if it's commented. Let's do necessary actions and
return no error explicitly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>