update docs

Signed-off-by: Nzengyawen <zengyawen1@huawei.com>

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

@@ -3000,7 +3000,6 @@ read(size: number, isBlockingRead: boolean, callback: AsyncCallback<ArrayBuffer\
 audioCapturer.read(bufferSize, true, async(err, buffer) => {
     if (!err) {
         console.log("Success in reading the buffer data");
-        var number = fileio.writeSync(fd, buffer);
     }
 };
 ```

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

@@ -1311,7 +1311,7 @@ disconnect(device: string): boolean
 
 ```js
 let a2dpSrc = bluetooth.getProfile(PROFILE_A2DP_SOURCE);
-let boolean ret = a2dpSrc.disconnect('XX:XX:XX:XX:XX:XX');
+let ret = a2dpSrc.disconnect('XX:XX:XX:XX:XX:XX');
 ```
 
 

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

@@ -563,7 +563,7 @@ on\(type: 'error', callback: ErrorCallback\): void
 **示例：**
 
 ```
-let udp = socket.constructUDPSocketInstance()
+let udp = socket.constructUDPSocketInstance();
 udp.on('error', err => {
 	console.log("on error, err:" + JSON.stringify(err))
 });
@@ -591,7 +591,7 @@ off\(type: 'error', callback?: ErrorCallback\): void
 **示例：**
 
 ```
-let udp = socket.constructUDPSocketInstance()
+let udp = socket.constructUDPSocketInstance();
 let callback = err =>{
 	console.log("on error, err:" + JSON.stringify(err));
 }