Output of tahoe deep-check --repair is hard to skim

[kpreid]

The summary output of tahoe deep-check looks exactly the same, except for the numbers, no matter whether everything is fine or files needed to be repaired. For easier scanning, especially in a log of multiple deep-check operations at different times or of different files, it should have fewer statements that there were 0 of something; for example, in the simple case of all files being healthy, a statement like “5 files checked and found healthy.” would be good, as opposed to the current:

done: 5 objects checked
 pre-repair: 5 healthy, 0 unhealthy
 0 repairs attempted, 0 successful, 0 failed
 post-repair: 5 healthy, 0 unhealthy

Also, the output does not include any feedback that --add-lease did its thing, but that is perhaps a separate issue.

[zooko]

Tagging this as "easy". (Feel free, kpreid or anyone, to untag it if this seems harder to you than "easy".)