can: at91_can: fix use after free of priv

The priv is part of the memory allocated by alloc_candev().
This patch moved the free it after last usage of priv.

While there convert all free_netdev() to free_candev() (which is currently
just a wrapper around free_netdev()) to be symetrically with the allocation
via alloc_candev().

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/at91_can.c

@@ -1101,7 +1101,7 @@ static int __init at91_can_probe(struct platform_device *pdev)
 	return 0;
 
  exit_free:
-	free_netdev(dev);
+	free_candev(dev);
  exit_iounmap:
 	iounmap(addr);
  exit_release:
@@ -1122,8 +1122,6 @@ static int __devexit at91_can_remove(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, NULL);
 
-	free_netdev(dev);
-
 	iounmap(priv->reg_base);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1131,6 +1129,8 @@ static int __devexit at91_can_remove(struct platform_device *pdev)
 
 	clk_put(priv->clk);
 
+	free_candev(dev);
+
 	return 0;
 }