ACPI: *really* fix ISO SCI override support (thanks again to John Stultz)

arch/i386/kernel/mpparse.c

@@ -1028,10 +1028,15 @@ void __init mp_config_ioapic_for_sci(int irq)
                 	if (entry->header.type == ACPI_MADT_INT_SRC_OVR &&
 			    acpi_fadt.sci_int == entry->bus_irq) {
 				/*
-				 * ACPI should use the settings in the
-				 * ISO for its SCI. Do not continue.
+				 * See the note at the end of ACPI 2.0b section
+				 * 5.2.10.8 for what this is about.
 				 */
+				if (entry->bus_irq != entry->global_irq) {
 					acpi_fadt.sci_int = entry->global_irq;
+					irq = entry->global_irq;
+					break;
+				}
+				else
                 			return;
 			}