RFR: 8326222: Fix copyright year in src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

[David Holmes]

Trivial fix to add back missing comma.

Thanks

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Commit messages:
 - 8326222: Fix copyright here in src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

Changes: https://git.openjdk.org/jdk/pull/17920/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17920&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326222
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17920.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17920/head:pull/17920

PR: https://git.openjdk.org/jdk/pull/17920