RFR: 8269225: JFR.stop misses the written info when the filename is only specified by JFR.start [v4]

[Denghui Dong]

> Hi,
> 
> Could I have a review of this small fix?
> 
> JFR.stop misses the written info when the filename is only specified by JFR.start, for example:
> 
> $jcmd 87802 JFR.start name=test filename=2.jfr
> 87802:
> Started recording 1. No limit specified, using maxsize=250MB as default.
> 
> Use jcmd 87802 JFR.dump name=test to copy recording data to file.
> 
> $jcmd 87802 JFR.stop name=test
> 87802:
> Stopped recording "test".
> 
> 
> The 'JFR.stop' didn't print written info, but actually, 2.jfr was generated.

Denghui Dong has updated the pull request incrementally with one additional commit since the last revision:

  remove useless import

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4573/files
  - new: https://git.openjdk.java.net/jdk/pull/4573/files/c1950b96..e9f18baa

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4573&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4573&range=02-03

  Stats: 4 lines in 2 files changed: 0 ins; 4 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4573.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4573/head:pull/4573

PR: https://git.openjdk.java.net/jdk/pull/4573