can: flexcan: flexcan_open(): fix error path if flexcan_chip_start() fails

commit 7e9e148a upstream.

If flexcan_chip_start() in flexcan_open() fails, the interrupt is not freed,
this patch adds the missing cleanup.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/net/can/flexcan.c

@@ -811,12 +811,14 @@ static int flexcan_open(struct net_device *dev)
 	/* start chip and queuing */
 	err = flexcan_chip_start(dev);
 	if (err)
-		goto out_close;
+		goto out_free_irq;
 	napi_enable(&priv->napi);
 	netif_start_queue(dev);
 
 	return 0;
 
+ out_free_irq:
+	free_irq(dev->irq, dev);
  out_close:
 	close_candev(dev);
  out: