jdk/jfr/tool/TestConfigure.java fails to cleanup the output files after the testing

The output files should be removed after the testing.

```
test/jdk/jdk/jfr/tool/1618403178745test-selection.jfc
test/jdk/jdk/jfr/tool/1618403180406test-text.jfc
test/jdk/jdk/jfr/tool/1618403181283test-flag.jfc
test/jdk/jdk/jfr/tool/1618403182099test-condition-1.jfc
test/jdk/jdk/jfr/tool/1618403182885test-condition-2.jfc
test/jdk/jdk/jfr/tool/1618403183598test-and-true.jfc
test/jdk/jdk/jfr/tool/1618403184320test-and-false.jfc
test/jdk/jdk/jfr/tool/1618403185068test-or-true.jfc
test/jdk/jdk/jfr/tool/1618403185738test-or-false.jfc
test/jdk/jdk/jfr/tool/1618403186440new.jfc
test/jdk/jdk/jfr/tool/1618403187198missed.jfc
test/jdk/jdk/jfr/tool/1618403187911fresh.jfc
test/jdk/jdk/jfr/tool/1618403188568new.jfc
test/jdk/jdk/jfr/tool/1618403189200test-superfluous.jfc
test/jdk/jdk/jfr/tool/1618403190777test-modify-succeed.jfc
test/jdk/jdk/jfr/tool/1618403191304test-adding-succeed-1.jfc
test/jdk/jdk/jfr/tool/1618403191787test-adding-succeed-2.jfc
test/jdk/jdk/jfr/tool/1618403192284combined.jfc
test/jdk/jdk/jfr/tool/1618403192834quoted-timespan.jfc
test/jdk/jdk/jfr/tool/1618403193319compact-timespan.jfc
test/jdk/jdk/jfr/tool/1618403193816threshold-period-timespan.jfc
test/jdk/jdk/jfr/tool/1618403194331verbose-1.jfc
test/jdk/jdk/jfr/tool/1618403194791verbose-2.jfc
```