message: remove used var
diff: @@ -1281,7 +1281,7 @@ void MemoryManager::UpdateMemoryType(void *h_ptr, const MemoryType mt)
  if (mem.d_mt == d_mt) { return; }
  MFEM_VERIFY(mem.d_ptr == nullptr,
  "Cannot change the memory type if d_ptr != nullptr");
  - auto old = maps->memories.erase(mem_map_iter);
  + maps->memories.erase(mem_map_iter);
  maps->memories.emplace(h_ptr, internal::Memory(h_ptr, mem.bytes, h_mt, d_mt));
  }
  