libahci: fix result_tf handling after an ATA PIO data-in command

libahci: fix result_tf handling after an ATA PIO data-in command

ATA devices don't send D2H Reg FIS after an successful ATA PIO data-in
command.  The host is supposed to take the TF and E_Status of the
preceding PIO Setup FIS.  Update ahci_qc_fill_rtf() such that it takes
TF + E_Status from PIO Setup FIS after a successful ATA PIO data-in
command.

Without this patch, result_tf for such a command is filled with the
content of the previous D2H Reg FIS which belongs to a previous
command, which can make the command incorrectly seen as failed.

* Patch updated to grab the whole TF + E_Status from PIO Setup FIS
  instead of just E_Status as suggested by Robert Hancock.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mark Lord <kernel@teksavvy.com>
Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>