add await for generatekey

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

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

@@ -983,7 +983,7 @@ async function attestKey() {
   let options = {
     properties: properties
   };
-  generateKey(aliasString);
+  await generateKey(aliasString);
   huks.attestKey(aliasString, options)
     .then((data) => {
       console.log(`test attestKey data: ${JSON.stringify(data)}`);