[SCSI] iscsi_transport, qla4xxx: have class lookup host for drivers

We are going to be adding more host level sysfs attrs and
set_params, so this patch has them take a scsi_host instead
of either a scsi_host or host no.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_iscsi.c

@@ -945,15 +945,26 @@ static int
 iscsi_tgt_dscvr(struct iscsi_transport *transport,
 		struct iscsi_uevent *ev)
 {
+	struct Scsi_Host *shost;
 	struct sockaddr *dst_addr;
+	int err;
 
 	if (!transport->tgt_dscvr)
 		return -EINVAL;
 
+	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
+	if (IS_ERR(shost)) {
+		printk(KERN_ERR "target discovery could not find host no %u\n",
+		       ev->u.tgt_dscvr.host_no);
+		return -ENODEV;
+	}
+
+
 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
-	return transport->tgt_dscvr(ev->u.tgt_dscvr.type,
-				    ev->u.tgt_dscvr.host_no,
-				    ev->u.tgt_dscvr.enable, dst_addr);
+	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
+				   ev->u.tgt_dscvr.enable, dst_addr);
+	scsi_host_put(shost);
+	return err;
 }
 
 static int