ata: libata-scsi: Check ATA_QCFLAG_RTF_FILLED before using result_tf

qc->result_tf contents are only valid when the ATA_QCFLAG_RTF_FILLED flag
is set. The ATA_QCFLAG_RTF_FILLED flag should be always set for commands
that failed or for commands that have the ATA_QCFLAG_RESULT_TF flag set.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Link: https://lore.kernel.org/r/20240702024735.1152293-8-ipylypiv@google.com


Signed-off-by: Niklas Cassel <cassel@kernel.org>