Status line isn't properly cleared on each update

[nk9]

The cursor is placed back at the beginning of the status line each time and new string is printed. However, it's only printed over top of the old string to the length of the new string. Since the length keeps changing, you end up with a status line which looks like this after it's been running for awhile:

 ⢹ [39724/65536 pages] [77.6MB/128.0MB] [0.5B/s] [ETA: 13h 8m 54s]]50s]
                                                                  ^^^^^ Note extra characters

The solution is to use one of these approaches to clear the line of previous characters before or during each print.