8273435: Remove redundant zero-length check in ClassDesc.of

Reviewed-by: rriggs

src/java.base/share/classes/java/lang/constant/ClassDesc.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 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
@@ -99,7 +99,7 @@ public sealed interface ClassDesc
         }
         validateMemberName(requireNonNull(className), false);
         return ofDescriptor("L" + binaryToInternal(packageName) +
-                (packageName.length() > 0 ? "/" : "") + className + ";");
+                "/" + className + ";");
     }
 
     /**