table: don't use shared_ptr in Measurements

refs #3164

Change-Id: I7705d00ac155b15b5db69809610b68e96360a0ae
diff --git a/daemon/fw/asf-measurements.hpp b/daemon/fw/asf-measurements.hpp
index 8339d97..64f88c2 100644
--- a/daemon/fw/asf-measurements.hpp
+++ b/daemon/fw/asf-measurements.hpp
@@ -294,8 +294,9 @@
   NamespaceInfo&
   getOrCreateNamespaceInfo(const fib::Entry& fibEntry, const ndn::Interest& interest);
 
+private:
   void
-  extendLifetime(shared_ptr<measurements::Entry> me);
+  extendLifetime(measurements::Entry& me);
 
 public:
   static constexpr time::microseconds MEASUREMENTS_LIFETIME = time::seconds(300);