Fix to cancel pending callbacks for closing ORB topics

src/modules/uORB/uORB.cpp

@@ -249,7 +249,8 @@ ORBDevNode::close(struct file *filp)
 	} else {
 		SubscriberData *sd = filp_to_sd(filp);
 
-		if (sd != nullptr)
+		if (sd != nullptr) {
+			hrt_cancel(&sd->update_call);
 			delete sd;
 		}