ExportReviewNotes: Fix synchronization on non-final field

When all error prone warnings are enabled the SynchronizeOnNonFinalField
bug pattern is reported:

  plugins/reviewnotes/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/ExportReviewNotes.java:110:
  error: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe:
  if the field is ever updated, different threads may end up locking on different objects.
    synchronized (changes) {
                 ^
    (see https://errorprone.info/bugpattern/SynchronizeOnNonFinalField)

Change-Id: Ie671af628f1ce60de53165048b80d88e2c4d26ae
1 file changed
tree: b8f0eecd792a9fa76d11c9c99e3ddb35ab12f639
  1. .gitignore
  2. .settings/
  3. BUILD
  4. LICENSE
  5. src/