[PATCH] libata: minor fix for 2.6.16-rc3

 - Fix the array index value in ata_rwcmd_protocol() for the added FUA commands.
 - Filter out ATAPI packet command error messages in ata_pio_error()

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>