rib: simplify ReadvertisedRoute

refs #3818

Change-Id: Ied644d825458f387b6f886bfcd425cffd2c2c7aa
diff --git a/rib/readvertise/readvertise-destination.hpp b/rib/readvertise/readvertise-destination.hpp
index 204d2b6..1bfaeb7 100644
--- a/rib/readvertise/readvertise-destination.hpp
+++ b/rib/readvertise/readvertise-destination.hpp
@@ -28,8 +28,6 @@
 
 #include "readvertised-route.hpp"
 
-#include <ndn-cxx/mgmt/nfd/controller.hpp>
-
 namespace nfd {
 namespace rib {
 
@@ -42,12 +40,12 @@
   ~ReadvertiseDestination() = default;
 
   virtual void
-  advertise(nfd::rib::ReadvertisedRoute& rr,
+  advertise(const ReadvertisedRoute& rr,
             std::function<void()> successCb,
             std::function<void(const std::string&)> failureCb) = 0;
 
   virtual void
-  withdraw(nfd::rib::ReadvertisedRoute& rr,
+  withdraw(const ReadvertisedRoute& rr,
            std::function<void()> successCb,
            std::function<void(const std::string&)> failureCb) = 0;
 
@@ -64,8 +62,7 @@
 public:
   /** \brief signals when the destination becomes available or unavailable
    */
-  ndn::util::signal::Signal<ReadvertiseDestination, bool>
-  afterAvailabilityChange;
+  signal::Signal<ReadvertiseDestination, bool> afterAvailabilityChange;
 
 private:
   bool m_isAvailable = false;