[SCSI] zfcp: fix layering oddities between zfcp_fsf and zfcp_qdio

There is no need for the QDIO layer to have knowledge or do things
wich are done better by the FSF layer and vice versa.  Straighten a
few things to improve vividness.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>