linux-phytec-fsl

libata-sff: prevent irq descriptions for dummy ports

This is a cosmetic change to prevent libata-sff adding irq
descriptions to dummy ports, since the information, while largely
unused, is erroneous.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>