sata_nv: cleanup ADMA error handling

This cleans up a few issues with the error handling in sata_nv in ADMA mode
to make it more consistent with other NCQ-capable drivers like ahci and
sata_sil24:

- When a command failed, we would effectively set AC_ERR_DEV on the
  queued command always.  In the case of NCQ commands this prevents libata
  from doing a log page query to determine the details of the failed
  command, since it thinks we've already analyzed.  Just set flags in the
  port ehi->err_mask, then freeze or abort and let libata figure out what
  went wrong.

- The code handled NV_ADMA_STAT_CPBERR as a "really bad error" which
  caused it to set error flags on every queued command.  I don't know
  exactly what this flag means (no docs, grr!) but from what I can guess
  from the standard ADMA spec, it just means that one or more of the CPBs
  had an error, so we just need to go through and do our normal checks in
  this case.

- In the error_handler function the code would always dump the state of
  all the CPBs.  This output seems redundant at this point since libata
  already dumps the state of all active commands on errors (and it also
  triggers at times when it shouldn't, like when suspending).  Take this
  out.

[akpm@osdl.org: many coding-style fixes]
Signed-off-by: Robert Hancock <hancockr@shaw.ca>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Allen Martin <AMartin@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>