[SCSI] zfcp: Use -EIO for SBAL allocation failures

-ENOMEM is for memory allocation problems, -EIO for queue/SBAL
allocation problems.

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