x86: ACPI: Make mp_config_acpi_gsi() a void function

Because the return value of mp_config_acpi_gsi() is not use, change it
into a void function.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/kernel/acpi/boot.c

@@ -375,7 +375,7 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
 	isa_irq_to_gsi[bus_irq] = gsi;
 }
 
-static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
+static void mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
 			int polarity)
 {
 #ifdef CONFIG_X86_MPPARSE
@@ -387,9 +387,9 @@ static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
 	u8 pin;
 
 	if (!acpi_ioapic)
-		return 0;
+		return;
 	if (!dev || !dev_is_pci(dev))
-		return 0;
+		return;
 
 	pdev = to_pci_dev(dev);
 	number = pdev->bus->number;
@@ -408,7 +408,6 @@ static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
 
 	mp_save_irq(&mp_irq);
 #endif
-	return 0;
 }
 
 static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,