RFR: 8259814: test/jdk/tools/jlink/plugins/CompressorPluginTest.java has compilation issues

[Athijegannathan Sundararajan]

Fixed compilation issues with the test. Test compiles and runs fine locally.

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Commit messages:
 - 8259814: test/jdk/tools/jlink/plugins/CompressorPluginTest.java has compilation issues

Changes: https://git.openjdk.java.net/jdk/pull/2091/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2091&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259814
  Stats: 16 lines in 1 file changed: 5 ins; 0 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2091.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2091/head:pull/2091

PR: https://git.openjdk.java.net/jdk/pull/2091