Rename 'src' directory to 'ndn-cxx'

Change-Id: I14394023680901a86977313ca87fb017333614dd
Refs: #3084
diff --git a/tools/ndnsec/util.hpp b/tools/ndnsec/util.hpp
index 61b6b52..65b88e7 100644
--- a/tools/ndnsec/util.hpp
+++ b/tools/ndnsec/util.hpp
@@ -22,11 +22,11 @@
 #ifndef NDN_TOOLS_NDNSEC_UTIL_HPP
 #define NDN_TOOLS_NDNSEC_UTIL_HPP
 
-#include "encoding/buffer-stream.hpp"
-#include "security/transform.hpp"
-#include "security/key-chain.hpp"
-#include "security/v2/additional-description.hpp"
-#include "util/io.hpp"
+#include <ndn-cxx/encoding/buffer-stream.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/security/transform.hpp>
+#include <ndn-cxx/security/v2/additional-description.hpp>
+#include <ndn-cxx/util/io.hpp>
 
 #include <fstream>
 #include <iostream>