!8468 【轻量级 PR】：update zh-cn/application-dev/reference/apis/js-apis-media.md.

Merge pull request !8468 from zengyawen/N/A

zh-cn/application-dev/reference/apis/js-apis-media.md

@@ -2004,7 +2004,7 @@ eventEmitter.on('prepare', () => {
 });
 
 media.createVideoRecorder((err, recorder) => {
-    if (err == null && recorder) != null) {
+    if (err == null && recorder != null) {
         videoRecorder = recorder;
         console.info('createVideoRecorder success');
         eventEmitter.emit('prepare');                                        // prepare事件触发