简化工具函数

packages/artplayer/src/player/currentTimeMix.js

@@ -1,7 +1,7 @@
-import { clamp } from '../utils';
+import { clamp, def } from '../utils';
 
 export default function currentTimeMix(art, player) {
-    Object.defineProperty(player, 'currentTime', {
+    def(player, 'currentTime', {
         get: () => art.template.$video.currentTime || 0,
         set: currentTime => {
             art.template.$video.currentTime = clamp(currentTime, 0, player.duration);