tests: Fix compilation due to refactoring of EncodingImpl in ndn-cxx library

Change-Id: I3b96dd01fef810dfd2cd57d910a46f137a13879e
Refs: #2494
diff --git a/tests/core/segment-publisher.cpp b/tests/core/segment-publisher.cpp
index 7a9ee1d..be28aba 100644
--- a/tests/core/segment-publisher.cpp
+++ b/tests/core/segment-publisher.cpp
@@ -73,7 +73,7 @@
     size_t totalLength = 0;
     for (int64_t i = 0; i < N; i++)
       {
-        totalLength += prependNonNegativeIntegerBlock(outBuffer, tlv::Content, i);
+        totalLength += ndn::prependNonNegativeIntegerBlock(outBuffer, tlv::Content, i);
       }
     m_totalPayloadLength += totalLength;
     return totalLength;