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

refs #3205

Change-Id: I8f227c57ee6733526f0569de81f20677210cafa4
diff --git a/daemon/fw/broadcast-strategy.cpp b/daemon/fw/broadcast-strategy.cpp
index 3a3249c..253efc8 100644
--- a/daemon/fw/broadcast-strategy.cpp
+++ b/daemon/fw/broadcast-strategy.cpp
@@ -40,9 +40,8 @@
 }
 
 void
-BroadcastStrategy::afterReceiveInterest(const Face& inFace,
-                   const Interest& interest,
-                   shared_ptr<pit::Entry> pitEntry)
+BroadcastStrategy::afterReceiveInterest(const Face& inFace, const Interest& interest,
+                                        const shared_ptr<pit::Entry>& pitEntry)
 {
   if (m_isFirstUse) {
     NFD_LOG_WARN("The broadcast strategy has been renamed as multicast strategy. "