What to do with quotacheck -l2 ?

I found a -l option in quotacheck this morning, which has been there
since revision 1.1 and never documented.  The option controls the
maximum number of concurrent filesystems that quotacheck will operate
on during the second pass, and should almost certainly be documented.

The -l option is ignored without -a, and using it without -a should
result in some kind of warning.  However, this behaviour has been
unchanged for the entire lifetime of quotacheck in FreeBSD and I'm
loathe to break anything, so I turn to you to see if this looks OK.

Patch attached, comments welcomed.

Thanks,

Ceri
-- 
That must be wonderful!  I don't understand it at all.
                                                  -- Moliere