[PATCH] ACPI: check parameter for NULL

ACPI still explodes on my old PII and stops it booting.

Anyway, it is oopsing in drivers/acpi/scan.c line 207 where element
(which is NULL) gets dereferenced.

The ACPI bios on this thing has always seemed to be pretty broken, but
this at least allows the 'power' button to continue to work (the only
reason why I want ACPI).

drivers/acpi/scan.c

@@ -204,6 +204,8 @@ acpi_bus_extract_wakeup_device_power_package (
 		return AE_BAD_PARAMETER;
 
 	element = &(package->package.elements[0]);
+	if (!element)
+		return AE_BAD_PARAMETER;
 	if (element->type == ACPI_TYPE_PACKAGE) {
 		if ((element->package.count < 2) ||
 			(element->package.elements[0].type != ACPI_TYPE_LOCAL_REFERENCE) ||