RFR: 8276199: java/nio/channels/FileChannel/LargeGatheringWrite.java fails to terminate correctly

[Brian Burkhalter]

Double the test timeout and remove the test from the ProblemList.

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Commit messages:
 - 8276199: java/nio/channels/FileChannel/LargeGatheringWrite.java fails to terminate correctly

Changes: https://git.openjdk.java.net/jdk/pull/6238/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6238&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8276199
  Stats: 3 lines in 2 files changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6238.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6238/head:pull/6238

PR: https://git.openjdk.java.net/jdk/pull/6238