RFR: 8220657: JFR.dump does not work when filename is set

[Yasumasa Suenaga]

Hi all,

Please review this change.

  JBS: https://bugs.openjdk.java.net/browse/JDK-8220657
  webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8220657/webrev.00/

The user might not get flight record via JFR.dump if JFR is started
with filename option on target process.

Please see JBS if you want to know how to reproduce.


Thanks,

Yasumasa