RFR: 8267937: Wrong indentation in G1 gc+phases log for free cset subphases

[Thomas Schatzl]

Hi all,

  JDK-8214327: Join parallel phases post evacuation messed up some indentation of logging:
  
The current gc+phases=trace looks as follows:
 ```
[0.059s][debug][gc,phases   ] GC(1)       Redirty Logged Cards (ms):     Min:  0.0, Avg:  0.0, Max:  0.0, Diff:  0.0, Sum:  0.0, Workers: 3
[0.059s][debug][gc,phases   ] GC(1)         Redirtied Cards:               Min: 0, Avg: 184.3, Max: 531, Diff: 531, Sum: 553, Workers: 3
[0.059s][debug][gc,phases   ] GC(1)       Free Collection Set (ms):      Min:  0.0, Avg:  0.0, Max:  0.0, Diff:  0.0, Sum:  0.0, Workers: 3
[0.059s][trace][gc,phases   ] GC(1)           Young Free Collection Set (ms): Min:  0.0, Avg:  0.0, Max:  0.0, Diff:  0.0, Sum:  0.0, Workers: 1
[0.059s][trace][gc,phases   ] GC(1)           Non-Young Free Collection Set (ms): skipped

`Young Free Collection Set` and `Non-Young Free Collection set` are indented one level too many.

This change fixes this.

Testing: manual testing, there is no indentation check for log messages

Thanks,
  Thomas

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

Commit messages:
 - Initial commit

Changes: https://git.openjdk.java.net/jdk/pull/4249/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4249&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267937
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4249.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4249/head:pull/4249

PR: https://git.openjdk.java.net/jdk/pull/4249