8296923: JFR: jfr --version should return System.getProperty("java version")

Reviewed-by: mgronlun

Author: egahlin

src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Version.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2022, 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
@@ -41,7 +41,7 @@ public String getDescription() {
 
     @Override
     public void execute(Deque<String> options) {
-        System.out.println("1.0");
+        System.out.println(System.getProperty("java.version"));
     }
 
     @Override