Fix the HSM error_mask mapping.

Changes:
- Better mapping in ac_err_mask()
- In HSM_ST_FIRST ans HSM_ST state, check ATA_ERR|ATA_DF and map it to AC_ERR_DEV instead of AC_ERR_HSM.
- In HSM_ST_FIRST and HSM_ST state, map DRQ=1 ERR=1 to AC_ERR_HSM.
- For PIO data in and DRQ=1 ERR=1, add check after the junk data block is read.
Signed-off-by: NAlbert Lee <albertcc@tw.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>