utils: Remove unnecessary semicolons to reduce warnings

Change-Id: I8b8848e360cdbdc279ae7f3e64cf2bf50768d379
diff --git a/utils/topology/rocketfuel-map-reader.hpp b/utils/topology/rocketfuel-map-reader.hpp
index 1c089f0..64428d7 100644
--- a/utils/topology/rocketfuel-map-reader.hpp
+++ b/utils/topology/rocketfuel-map-reader.hpp
@@ -181,6 +181,6 @@
   assignGw(Traits::vertex_descriptor vertex, uint32_t degree, node_type_t nodeType);
 }; // end class RocketfuelMapReader
 
-}; // end namespace ns3
+}  // end namespace ns3
 
 #endif /* ROCKETFUEL_MAP_READER_H */