RFR: 8323710: (fc) FileChannel.lock creates a FileKey with a poor hashCode after JDK-8321429 (win)

[Brian Burkhalter]

Dispense with the shift operators in calculating the hash code of `FileKey`.

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Commit messages:
 - 8323710: (fc) FileChannel.lock creates a FileKey with a poor hashCode after JDK-8321429 (win)

Changes: https://git.openjdk.org/jdk/pull/17452/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17452&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8323710
  Stats: 5 lines in 1 file changed: 0 ins; 3 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17452.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17452/head:pull/17452

PR: https://git.openjdk.org/jdk/pull/17452