[SCSI] zfcp: Return -ENOMEM for allocation failures in zfcp_fsf

When a fsf_req or a qtcb cannot be allocated return -ENOMEM instead of
-EIO.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/s390/scsi/zfcp_fsf.c

@@ -722,7 +722,7 @@ static struct zfcp_fsf_req *zfcp_fsf_req_create(struct zfcp_adapter *adapter,
 		req = zfcp_fsf_alloc_qtcb(pool);
 
 	if (unlikely(!req))
-		return ERR_PTR(-EIO);
+		return ERR_PTR(-ENOMEM);
 
 	if (adapter->req_no == 0)
 		adapter->req_no++;