[jdk8u-dev] RFR: 8335851: [8u] Test JMXStartStopTest.java fails after JDK-8334415

[SendaoYan]

Hi all,
The testcase `sun/management/jmxremote/startstop/JMXStartStopTest.java` compile error after [JDK-8334415](https://bugs.openjdk.org/browse/JDK-8334415). This PR fix the testcase bug, the change has been verified, no risk.

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Commit messages:
 - 8335851: [8u] Test JMXStartStopTest.java fails after JDK-8334415

Changes: https://git.openjdk.org/jdk8u-dev/pull/541/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=541&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335851
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/541.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/541/head:pull/541

PR: https://git.openjdk.org/jdk8u-dev/pull/541