Fix findings from check-in on r374177

Richard pointed out two problems with the check-in from r374177:
* The ast_msg_shutdown function declaration doesn't match the prototype
  in main/message.c.
* The ref/alloc function usage in astobj2 (in 11+) can use the ao2_t_* variants
  of the functions to allow the REF_DEBUG flag to enable/disable their debug
  counterparts.



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@374210 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/message.c

@@ -1113,7 +1113,7 @@ int ast_msg_tech_unregister(const struct ast_msg_tech *tech)
 	return 0;
 }
 
-void ast_msg_shutdown()
+void ast_msg_shutdown(void)
 {
 	if (msg_q_tp) {
 		msg_q_tp = ast_taskprocessor_unreference(msg_q_tp);