RFR: 8263480: ProblemList two jpackage tests on Windows

[Daniel D.Daugherty]

A trivial fix to ProblemList two new tests on Windows.

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Commit messages:
 - 8263480: ProblemList two jpackage tests on Windows

Changes: https://git.openjdk.java.net/jdk/pull/2952/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2952&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263480
  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2952.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2952/head:pull/2952

PR: https://git.openjdk.java.net/jdk/pull/2952