message: sync: print proper lock order location when double lock is detected
  Before:
  ```
  Assertion failed: detected double lock at src/sync.cpp:153, details in debug log.
  ```
  After:
  ```
  Assertion failed: detected double lock for 'm' in src/test/sync_tests.cpp:40 (in thread ''), details in debug log.
  ```
diff: @@ -150,7 +150,9 @@ static void double_lock_detected(const void* mutex, LockStack& lock_stack)
  LogPrintf(" %s\n", i.second.ToString());
  }
  if (g_debug_lockorder_abort) {
  - tfm::format(std::cerr, "Assertion failed: detected double lock at %s:%i, details in debug log.\n", __FILE__, __LINE__);
  + tfm::format(std::cerr,
  + "Assertion failed: detected double lock for %s, details in debug log.\n",
  + lock_stack.back().second.ToString());
  abort();
  }
  throw std::logic_error("double lock detected");
  