tlv: Use the encoding/decoding functions for "double" from ndn-cxx

refs: #4615

Change-Id: I0bde7085876646f272ee6006f4d3cfbd513d4ffd
diff --git a/tests/tlv/test-routing-table.cpp b/tests/tlv/test-routing-table.cpp
index 85a9850..6e9ce43 100644
--- a/tests/tlv/test-routing-table.cpp
+++ b/tests/tlv/test-routing-table.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014-2018,  The University of Memphis,
+ * Copyright (c) 2014-2019,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -32,14 +32,14 @@
 const uint8_t RoutingTableData1[] =
 {
   // Header
-  0x90, 0x24,
+  0x90, 0x22,
   // Routing table entry
-  0x91, 0x22,
-    // Destination
-    0x8e, 0x09, 0x07, 0x07, 0x08, 0x05, 0x64, 0x65, 0x73, 0x74, 0x31,
-    // Nexthop
-    0x8f, 0x15, 0x8d, 0x07, 0x6e, 0x65, 0x78, 0x74, 0x68, 0x6f, 0x70,
-    0x86, 0x0a, 0x86, 0x08, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0xfa, 0x3f
+  0x91, 0x20,
+  // Destination
+  0x8e, 0x09, 0x07, 0x07, 0x08, 0x05, 0x64, 0x65, 0x73, 0x74, 0x31,
+  // Nexthop
+  0x8f, 0x13, 0x8d, 0x07, 0x6e, 0x65, 0x78, 0x74, 0x68, 0x6f, 0x70, 0x86, 0x08, 0x3f,
+  0xfa, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66
 };
 
 const uint8_t RoutingTableData2[] =