devclass_find_free_unit

[Peter Grehan]

Hi Warner,

> What purpose does devclass_find_free_unit serve?  I think it can safely be
> eliminated from the tree.  The current design is racy.
  ...
> ./powerpc/psim/.svn/text-base/ata_iobus.c

  That would be a cut'n'paste relic from the ATA code that it originated 
from. Going to -1 is fine.

later,

Peter.