common: remove DECL_FINAL/OVERRIDE macros; use C++11 keywords directly

Change-Id: I71a148b0df7c95387b2caa8e2b9fe93b03ca2399
Refs: #3599
diff --git a/daemon/mgmt/nfd-manager-base.hpp b/daemon/mgmt/nfd-manager-base.hpp
index 4104fbe..6273624 100644
--- a/daemon/mgmt/nfd-manager-base.hpp
+++ b/daemon/mgmt/nfd-manager-base.hpp
@@ -70,7 +70,7 @@
   authorize(const Name& prefix, const Interest& interest,
             const ndn::mgmt::ControlParameters* params,
             ndn::mgmt::AcceptContinuation accept,
-            ndn::mgmt::RejectContinuation reject) DECL_OVERRIDE;
+            ndn::mgmt::RejectContinuation reject) override;
 
 private:
   CommandValidator& m_validator;