chunks: fix impossible RTT values

Change-Id: Ia7386c6186362be5c50ea291a949fd40ec0224b4
Refs: #4604
diff --git a/tools/chunks/catchunks/pipeline-interests.cpp b/tools/chunks/catchunks/pipeline-interests.cpp
index 68e0157..2318378 100644
--- a/tools/chunks/catchunks/pipeline-interests.cpp
+++ b/tools/chunks/catchunks/pipeline-interests.cpp
@@ -79,6 +79,13 @@
   doCancel();
 }
 
+bool
+PipelineInterests::allSegmentsReceived() const
+{
+  BOOST_ASSERT(m_nReceived > 0);
+  return m_hasFinalBlockId && static_cast<uint64_t>(m_nReceived - 1) >= m_lastSegmentNo;
+}
+
 uint64_t
 PipelineInterests::getNextSegmentNo()
 {