ACPICA: Remove argument of acpi_os_wait_events_complete

Remove the unused argument of acpi_os_wait_events_complete.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index eb6fd23..9a14f90 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -144,7 +144,7 @@
 static int acpi_pm_freeze(void)
 {
 	acpi_disable_all_gpes();
-	acpi_os_wait_events_complete(NULL);
+	acpi_os_wait_events_complete();
 	acpi_ec_block_transactions();
 	return 0;
 }