ACPI: processor: refactor internal map_lapic_id()

Untangle the if() statement a little for readability.
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/processor_core.c

@@ -50,12 +50,15 @@ static int map_lapic_id(struct acpi_subtable_header *entry,
 {
 	struct acpi_madt_local_apic *lapic =
 		(struct acpi_madt_local_apic *)entry;
-	if ((lapic->lapic_flags & ACPI_MADT_ENABLED) &&
-	    lapic->processor_id == acpi_id) {
+
+	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
+		return 0;
+
+	if (lapic->processor_id != acpi_id)
+		return 0;
+
 	*apic_id = lapic->id;
 	return 1;
-	}
-	return 0;
 }
 
 static int map_x2apic_id(struct acpi_subtable_header *entry,