Properly remove references to events when destroying

After destroying the check events, references to those events must be
cleared. If not, scheduling a new check event will try to destroy the
event that is still referenced, which causes a segfault.

src/naemon/checks_host.c

@@ -188,6 +188,9 @@ static void handle_host_check_event(struct nm_event_execution_properties *evprop
 			/* update the status log */
 			update_host_status(hst, FALSE);
 		}
+	} else if (evprop->execution_type == EVENT_EXEC_ABORTED) {
+		/* If the event is destroyed, remove the reference. */
+		hst->next_check_event = NULL;
 	}
 }
 

src/naemon/checks_service.c

@@ -240,6 +240,9 @@ static void handle_service_check_event(struct nm_event_execution_properties *evp
 
 		/* Otherwise, run the event */
 		run_scheduled_service_check(temp_service, options, latency);
+	} else if (evprop->execution_type == EVENT_EXEC_ABORTED) {
+		/* If the event is destroyed, remove the reference. */
+		temp_service->next_check_event = NULL;
 	}
 }