5144 format should trust blkdev
Reviewed by: Adam Števko <adam.stevko@gmail.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Marcel Telka <marcel@telka.sk>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Dan McDonald <danmcd@omniti.com>