fw: pass const shared_ptr<pit::Entry>& to Strategy triggers

refs #3205

Change-Id: I8f227c57ee6733526f0569de81f20677210cafa4
diff --git a/daemon/fw/best-route-strategy2.hpp b/daemon/fw/best-route-strategy2.hpp
index d78baf6..a27664f 100644
--- a/daemon/fw/best-route-strategy2.hpp
+++ b/daemon/fw/best-route-strategy2.hpp
@@ -52,17 +52,16 @@
 class BestRouteStrategy2 : public Strategy
 {
 public:
+  explicit
   BestRouteStrategy2(Forwarder& forwarder, const Name& name = STRATEGY_NAME);
 
   virtual void
   afterReceiveInterest(const Face& inFace, const Interest& interest,
-
-                       shared_ptr<pit::Entry> pitEntry) override;
+                       const shared_ptr<pit::Entry>& pitEntry) override;
 
   virtual void
   afterReceiveNack(const Face& inFace, const lp::Nack& nack,
-
-                   shared_ptr<pit::Entry> pitEntry) override;
+                   const shared_ptr<pit::Entry>& pitEntry) override;
 
 public:
   static const Name STRATEGY_NAME;