code style fix

Change-Id: I2f57ac1eb9c01063752adfc452ff0f1db3367fe3
diff --git a/src/name-assignment/assignment-func.hpp b/src/name-assignment/assignment-func.hpp
index 7a45e93..a574d05 100644
--- a/src/name-assignment/assignment-func.hpp
+++ b/src/name-assignment/assignment-func.hpp
@@ -18,8 +18,8 @@
  * See AUTHORS.md for complete list of ndncert authors and contributors.
  */
 
-#ifndef NDNCERT_ASSIGNMENT_FUNCS_HPP
-#define NDNCERT_ASSIGNMENT_FUNCS_HPP
+#ifndef NDNCERT_ASSIGNMENT_FUNC_HPP
+#define NDNCERT_ASSIGNMENT_FUNC_HPP
 
 #include "detail/ca-request-state.hpp"
 
@@ -82,4 +82,4 @@
 } // namespace ndncert
 } // namespace ndn
 
-#endif // NDNCERT_ASSIGNMENT_FUNCS_HPP
+#endif // NDNCERT_ASSIGNMENT_FUNC_HPP