[KYUUBI #1332] Fix regenerate document hint

### _Why are the changes needed?_

The previous command does not work after #1131.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [ ] [Run test](https://kyuubi.readthedocs.io/en/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #1332 from pan3793/hint.

Closes #1332

1c21a54a [Cheng Pan] Fix regenerate document hint

Authored-by: Cheng Pan <chengpan@apache.org>
Signed-off-by: Cheng Pan <chengpan@apache.org>

kyuubi-common/src/test/scala/org/apache/kyuubi/TestUtils.scala

@@ -50,8 +50,8 @@ object TestUtils {
         line = reader.readLine()
       }
       reader.close()
-      val hint = s"$markdown out of date, please update doc with build/mvn test" +
-        s" -DwildcardSuites=$agent"
+      val hint = s"$markdown out of date, please update doc with " +
+        s"KYUUBI_UPDATE=1 build/mvn clean install -Pspark-provided -DwildcardSuites=$agent"
       assert(newOutput.size === expected.size, hint)
 
       newOutput.zip(expected).foreach { case (out, in) => assert(out === in, hint) }