8263105: security-libs doclint cleanup

Reviewed-by: iris, darcy, dfuchs, mullan

src/java.base/share/classes/java/security/Timestamp.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -155,7 +155,14 @@ public final class Timestamp implements Serializable {
         return sb.toString();
     }
 
-    // Explicitly reset hash code value to -1
+    /**
+     * Restores the state of this object from the stream, and explicitly
+     * resets hash code value to -1.
+     *
+     * @param  ois the {@code ObjectInputStream} from which data is read
+     * @throws IOException if an I/O error occurs
+     * @throws ClassNotFoundException if a serialized class cannot be loaded
+     */
     @java.io.Serial
     private void readObject(ObjectInputStream ois)
         throws IOException, ClassNotFoundException {