table: Store shared_ptr<Interest> instead of just Interest to avoid extra copy

Change-Id: I240ea4cbe2c9e14b4c1ca2df87d40da8042b78d1
Refs: #1753
diff --git a/daemon/table/pit-in-record.hpp b/daemon/table/pit-in-record.hpp
index 88fa1f3..da56d1f 100644
--- a/daemon/table/pit-in-record.hpp
+++ b/daemon/table/pit-in-record.hpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,7 +21,7 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #ifndef NFD_DAEMON_TABLE_PIT_IN_RECORD_HPP
 #define NFD_DAEMON_TABLE_PIT_IN_RECORD_HPP
@@ -46,7 +47,7 @@
   getInterest() const;
 
 private:
-  shared_ptr<Interest> m_interest;
+  shared_ptr<const Interest> m_interest;
 };
 
 inline const Interest&