7127524: P11TlsPrfGenerator has anonymous inner class with serialVersionUID

Reviewed-by: vinnie

src/share/classes/sun/security/pkcs11/P11TlsPrfGenerator.java

 /*
- * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2013, 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
@@ -96,10 +96,15 @@ final class P11TlsPrfGenerator extends KeyGeneratorSpi {
         }
     }
 
-    // SecretKeySpec does not allow zero length keys, so we define our own class.
+    // SecretKeySpec does not allow zero length keys, so we define our
+    // own class.
+    //
+    // As an anonymous class cannot make any guarantees about serialization
+    // compatibility, it is nonsensical for an anonymous class to define a
+    // serialVersionUID. Suppress warnings relative to missing serialVersionUID
+    // field in the anonymous subclass of serializable SecretKey.
+    @SuppressWarnings("serial")
     private static final SecretKey NULL_KEY = new SecretKey() {
-        private static final long serialVersionUID = -8090049519656411362L;
-
         public byte[] getEncoded() {
             return new byte[0];
         }