modify the demo code

Signed-off-by: Nzhangwenzhi <zhangwenzhi3@huawei.com>

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

@@ -822,9 +822,9 @@ async function attestKey() {
     properties: properties
   };
   generateKey(aliasString);
-  setTimeout(()=>huks.attestKey(aliasString, options, function (err, data) {
+  huks.attestKey(aliasString, options, function (err, data) {
     printLog(`key attest result : ${JSON.stringify(data)}`);
-  }), 1000);
+  });
 }
 ```
 
@@ -894,8 +894,13 @@ async function attestKey() {
     properties: properties
   };
   generateKey(aliasString);
-  let result = await huks.exportKey(attestKey, options);
-  printLog(`key attest result : ${result.errorCode}`);
+  huks.attestKey(aliasString, options)
+    .then((data) => {
+      console.log(`test attestKey data: ${JSON.stringify(data)}`);
+    })
+    .catch((err) => {
+      console.log('test attestKey information: ' + JSON.stringify(err));
+    });
 }
 ```