[OpenAFS] fs sa -acl username all -dir $MNT failure

[Chris McClimans]

 From an attempt to add an acl to /afs/cs.ttu.edu/user/$USER:

# fs sa -acl wwelsh all -dir /afs/cs.ttu.edu/user/wwelsh
fs: Invalid argument, possible reasons include:
         -File not in AFS
         -Too many users on access control list
         -Tried to add non-existent user to access control list

# pts examine wwelsh
Name: wwelsh, id: 10543458, owner: system:administrators, creator: 
system:administrators,
   membership: 0, flags: S----, group quota: 20.

# fs examine wwelsh
Volume status for vid = 536871345 named user.wwelsh
Current disk quota is 100000
Current blocks used are 2
The partition has 329697716 blocks available out of 329777536

# ls -la wwelsh/
total 16
drwxrwxrwx    2 10543458 root         2048 Aug 27 21:46 .
drwxrwxrwx    2 root     root        14336 Aug 27 21:55 ..