input: Write a python function to sort a linked list in ascending order.
  assert linked_list_sort([4, 2, 1, 3]) == [1, 2, 3, 4]
  assert linked_list_sort([10, 5, 15, 0, 25]) == [0, 5, 10, 15, 25]
  assert linked_list_sort([1, 1, 1]) == [1, 1, 1]
output: def linked_list_sort(lst):
      if not lst:
          return lst
      lst.sort()
      return lst