face: fix warnings in NDNLP code

refs #1262

Change-Id: Iec17e22eefb04ee69f917c2826a1550906062013
diff --git a/daemon/face/ndnlp-partial-message-store.cpp b/daemon/face/ndnlp-partial-message-store.cpp
index 22b493b..df8a285 100644
--- a/daemon/face/ndnlp-partial-message-store.cpp
+++ b/daemon/face/ndnlp-partial-message-store.cpp
@@ -35,6 +35,7 @@
   m_payloads[fragIndex] = payload;
   ++m_received;
   m_totalLength += payload.value_size();
+  return true;
 }
 
 bool