ACPI: fix boot oops regression in thermal

Fix a memory overflow bug when copying
NULL internal package element object to external.

http://bugzilla.kernel.org/show_bug.cgi?id=10132

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/utilities/utobject.c

@@ -432,7 +432,7 @@ acpi_ut_get_simple_object_size(union acpi_operand_object *internal_object,
 	 * element -- which is legal)
 	 */
 	if (!internal_object) {
-		*obj_length = 0;
+		*obj_length = sizeof(union acpi_object);
 		return_ACPI_STATUS(AE_OK);
 	}