Fix cppcheck warnings

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: If5d808b9cb3bc733e7e21d546247d745ac5e1bf8
diff --git a/src/snmp_trap.hpp b/src/snmp_trap.hpp
index 34169b8..d21b805 100644
--- a/src/snmp_trap.hpp
+++ b/src/snmp_trap.hpp
@@ -62,14 +62,14 @@
     /** @brief Callback interface implementation.
      *  @param[in] ctc - context.
      */
-    void operator()(Context ctx)
+    void operator()(Context /* ctx */)
     {}
 
     /** @brief Callback interface implementation.
      *  @param[in] ctc - context.
      *  @param[in] msg - sdbus message.
      */
-    void operator()(Context ctx, sdbusplus::message::message& msg)
+    void operator()(Context /* ctx */, sdbusplus::message::message& msg)
     {
         event.trap(msg);
     }