face: eliminate Transport::Packet wrapper type

Refs: #4843
Change-Id: I5977be55e8bdac33c989e3b8523fea764f304c37
diff --git a/daemon/face/link-service.cpp b/daemon/face/link-service.cpp
index 34abd58..a382ebe 100644
--- a/daemon/face/link-service.cpp
+++ b/daemon/face/link-service.cpp
@@ -52,66 +52,66 @@
 }
 
 void
-LinkService::sendInterest(const Interest& interest, const EndpointId& endpointId)
+LinkService::sendInterest(const Interest& interest, const EndpointId& endpoint)
 {
   BOOST_ASSERT(m_transport != nullptr);
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nOutInterests;
 
-  doSendInterest(interest, endpointId);
+  doSendInterest(interest, endpoint);
 }
 
 void
-LinkService::sendData(const Data& data, const EndpointId& endpointId)
+LinkService::sendData(const Data& data, const EndpointId& endpoint)
 {
   BOOST_ASSERT(m_transport != nullptr);
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nOutData;
 
-  doSendData(data, endpointId);
+  doSendData(data, endpoint);
 }
 
 void
-LinkService::sendNack(const ndn::lp::Nack& nack, const EndpointId& endpointId)
+LinkService::sendNack(const ndn::lp::Nack& nack, const EndpointId& endpoint)
 {
   BOOST_ASSERT(m_transport != nullptr);
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nOutNacks;
 
-  doSendNack(nack, endpointId);
+  doSendNack(nack, endpoint);
 }
 
 void
-LinkService::receiveInterest(const Interest& interest, const EndpointId& endpointId)
+LinkService::receiveInterest(const Interest& interest, const EndpointId& endpoint)
 {
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nInInterests;
 
-  afterReceiveInterest(interest, endpointId);
+  afterReceiveInterest(interest, endpoint);
 }
 
 void
-LinkService::receiveData(const Data& data, const EndpointId& endpointId)
+LinkService::receiveData(const Data& data, const EndpointId& endpoint)
 {
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nInData;
 
-  afterReceiveData(data, endpointId);
+  afterReceiveData(data, endpoint);
 }
 
 void
-LinkService::receiveNack(const ndn::lp::Nack& nack, const EndpointId& endpointId)
+LinkService::receiveNack(const ndn::lp::Nack& nack, const EndpointId& endpoint)
 {
   NFD_LOG_FACE_TRACE(__func__);
 
   ++this->nInNacks;
 
-  afterReceiveNack(nack, endpointId);
+  afterReceiveNack(nack, endpoint);
 }
 
 void