rib: stop using the global scheduler

Change-Id: I0e205e2f1adf85be49b132b47791b27e4530697a
Refs: #4528
diff --git a/rib/rib-entry.cpp b/rib/rib-entry.cpp
index d59338d..008ac4f 100644
--- a/rib/rib-entry.cpp
+++ b/rib/rib-entry.cpp
@@ -116,8 +116,8 @@
     }
 
     // Cancel any scheduled event
-    NFD_LOG_TRACE("Cancelling expiration eventId: " << route->getExpirationEvent());
-    scheduler::cancel(route->getExpirationEvent());
+    NFD_LOG_TRACE("Cancelling expiration event: " << route->getExpirationEvent());
+    route->cancelExpirationEvent();
 
     return m_routes.erase(route);
   }