[OpenAFS] On the wording "No space left on device"

[Jeff Blaine]

We had a user complain this week about having no clue what
"No space left on device" meant.

Regardless of this particular user's inability to deduce
that there was "NO SPACE LEFT", I like to take these
opportunities to consider improvements.

"Disk, partition, or volume has insufficient free space"

Better yet, why does it have to be so vague?  Can't it
determine the actual problem, at least for the 90% case
of quota limit?

"Quota for volume u.jblaine has been exceeded."