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

If flexcan_chip_start() in flexcan_open() fails, the interrupt is not freed,
this patch adds the missing cleanup.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index dcd69c9..30af702 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -868,7 +868,7 @@
 	/* start chip and queuing */
 	err = flexcan_chip_start(dev);
 	if (err)
-		goto out_close;
+		goto out_free_irq;
 
 	can_led_event(dev, CAN_LED_EVENT_OPEN);
 
@@ -877,6 +877,8 @@
 
 	return 0;
 
+ out_free_irq:
+	free_irq(dev->irq, dev);
  out_close:
 	close_candev(dev);
  out_disable_per: