ACPI: Do not pass NULL to acpi_get_handle() when looking for _EJD

When trying to get the acpi_handle from an acpi_buffer, pass
ACPI_ROOT_OBJECT instead of NULL to acpi_get_handle(). This fixes the
detection of dock dependent bays.
Signed-off-by: Holger Macht <hmacht@suse.de>
Tested-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/scan.c

@@ -609,7 +609,8 @@ acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 	if (ACPI_SUCCESS(status)) {
 		obj = buffer.pointer;
-		status = acpi_get_handle(NULL, obj->string.pointer, ejd);
+		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
+					 ejd);
 		kfree(buffer.pointer);
 	}
 	return status;