x86: acpi: Return table length in acpi_create_madt_lapics()

Like other MADT table write routines, make acpi_create_madt_lapics()
return how many bytes it has written instead of the table end addr.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/x86/include/asm/acpi_table.h

@@ -301,7 +301,7 @@ struct acpi_mcfg_mmconfig {
 void acpi_fill_header(struct acpi_table_header *header, char *signature);
 void acpi_create_fadt(struct acpi_fadt *fadt, struct acpi_facs *facs,
 		      void *dsdt);
-u32 acpi_create_madt_lapics(u32 current);
+int acpi_create_madt_lapics(u32 current);
 int acpi_create_madt_ioapic(struct acpi_madt_ioapic *ioapic, u8 id,
 			    u32 addr, u32 gsi_base);
 int acpi_create_madt_irqoverride(struct acpi_madt_irqoverride *irqoverride,

arch/x86/lib/acpi_table.c

@@ -179,21 +179,23 @@ static int acpi_create_madt_lapic(struct acpi_madt_lapic *lapic,
 	return lapic->length;
 }
 
-u32 acpi_create_madt_lapics(u32 current)
+int acpi_create_madt_lapics(u32 current)
 {
 	struct udevice *dev;
+	int length = 0;
 
 	for (uclass_find_first_device(UCLASS_CPU, &dev);
 	     dev;
 	     uclass_find_next_device(&dev)) {
 		struct cpu_platdata *plat = dev_get_parent_platdata(dev);
 
-		current += acpi_create_madt_lapic(
+		length += acpi_create_madt_lapic(
 			(struct acpi_madt_lapic *)current,
 			plat->cpu_id, plat->cpu_id);
+		current += length;
 	}
 
-	return current;
+	return length;
 }
 
 int acpi_create_madt_ioapic(struct acpi_madt_ioapic *ioapic, u8 id,