message: global_heap: don't shadow mh in unlikely branch
diff: @@ -70,7 +70,7 @@ void GlobalHeap::free(void *ptr) {
  // global lock to synchronize with a concurrent mesh, and
  // re-update the bitmap
  lock_guard<mutex> lock(_miniheapLock);
  - auto mh = miniheapForLocked(ptr);
  + mh = miniheapForLocked(ptr);
  hard_assert(!mh->isMeshed());
  mh->free(arenaBegin(), ptr);
  }
  