SCSI/aha1740: handle SCSI API errors

index c3c38a7..d7af9c6 100644
@@ -586,7 +586,7 @@ static struct scsi_host_template aha1740
 
 static int aha1740_probe (struct device *dev)
 {
-	int slotbase;
+	int slotbase, rc;
 	unsigned int irq_level, irq_type, translation;
 	struct Scsi_Host *shpnt;
 	struct aha1740_hostdata *host;

@@ -641,10 +641,16 @@ static int aha1740_probe (struct device 
 	}
 
 	eisa_set_drvdata (edev, shpnt);
-	scsi_add_host (shpnt, dev); /* XXX handle failure */
+
+	rc = scsi_add_host (shpnt, dev);
+	if (rc)
+		goto err_irq;
+
 	scsi_scan_host (shpnt);
 	return 0;
 
+ err_irq:
+ 	free_irq(irq_level, shpnt);
  err_unmap:
 	dma_unmap_single (&edev->dev, host->ecb_dma_addr,
 			  sizeof (host->ecb), DMA_BIDIRECTIONAL);