Fixes unused variables

add_on/scripthelper/scripthelper.cpp

@@ -982,6 +982,7 @@ void RegisterExceptionRoutines(asIScriptEngine *engine)
 
 	r = engine->RegisterGlobalFunction("void throw(const string &in)", asFUNCTION(ScriptThrow), asCALL_CDECL); assert(r >= 0);
 	r = engine->RegisterGlobalFunction("string getExceptionInfo()", asFUNCTION(ScriptGetExceptionInfo), asCALL_CDECL); assert(r >= 0);
+    (void)r;
 }
 
 END_AS_NAMESPACE