message: Handle rename failure in DumpMempool(...) by using RenameOver(...) return value
diff: @@ -4803,7 +4803,9 @@ bool DumpMempool(const CTxMemPool& pool)
  if (!FileCommit(file.Get()))
  throw std::runtime_error("FileCommit failed");
  file.fclose();
  - RenameOver(GetDataDir() / "mempool.dat.new", GetDataDir() / "mempool.dat");
  + if (!RenameOver(GetDataDir() / "mempool.dat.new", GetDataDir() / "mempool.dat")) {
  + throw std::runtime_error("Rename failed");
  + }
  int64_t last = GetTimeMicros();
  LogPrintf("Dumped mempool: %gs to copy, %gs to dump\n", (mid-start)*MICRO, (last-mid)*MICRO);
  } catch (const std::exception& e) {
  