insane.bbclass: Correct package_qa_check_empty_dirs()

The oe.qa.add_message() method is not available in Honister, use
package_qa_add_message() instead.

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>