Separate out parts of ata_scsi_find_dev to be reused in
future SAS/SATA patches.
Acked-by: NJeff Garzik <jgarzik@pobox.com>
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>