message: Do not heap-allocate for hold status on critical path.
diff: @@ -1274,7 +1274,7 @@ PjRtStreamExecutorBuffer::GetBufferWithHold(ScopedHold::Type type) {
  absl::MutexLock lock(&mu_);
  ScopedHold hold(this, type);
  AcquireHoldLocked(&hold);
  - if (type == ScopedHold::kDonation && !hold.status().ok()) {
  + if (type == ScopedHold::kDonation && !hold.ok()) {
  donation_semaphore_.Release(1);
  }
  return hold;
  