[script] Use a pre computed value rather than accessing directly

The name_exp was already set to the thing we wanted, so use that. Less
confusing since other sections use it.

src/plugins/splash/script/script-execute.c

@@ -323,7 +323,7 @@ static script_obj_t *script_evaluate_func (script_state_t *state,
     }
   else
     {
-      func_obj = script_evaluate (state, exp->data.function_exe.name);
+      func_obj = script_evaluate (state, name_exp);
     }
   
   ply_list_t *parameter_expressions = exp->data.function_exe.parameters;