Improve horizontal alignment in long format when printing minor

Improve horizontal alignment in long format when printing minor
device numbers greater than 999 by measuring the two widths needed
for device numbers just like it is already done for other numbers.
In the output, this only changes whitespace, but not the text.

Ugly formatting reported by
Crystal Kolipe <kolipe dot c at exoticsilicon dot com>.

OK millert.  Also tested by Crystal Kolipe.