ACPI / processor: Fix acpi_processor_eval_pdc() return value type

The return value type of acpi_processor_eval_pdc() should be
'acpi_status' but is defined as 'int', so fix it.
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/processor_core.c

@@ -323,7 +323,7 @@ static struct acpi_object_list *acpi_processor_alloc_pdc(void)
  * _PDC is required for a BIOS-OS handshake for most of the newer
  * ACPI processor features.
  */
-static int
+static acpi_status
 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 {
 	acpi_status status = AE_OK;