can: c_can: checking IS_ERR() instead of NULL

devm_ioremap() returns NULL on error, not an ERR_PTR().

Fixes: 33cf7565 ('can: c_can_platform: Fix raminit, use devm_ioremap() instead of devm_ioremap_resource()')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.11
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/c_can/c_can_platform.c

@@ -280,7 +280,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 
 		priv->raminit_ctrlreg = devm_ioremap(&pdev->dev, res->start,
 						     resource_size(res));
-		if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
+		if (!priv->raminit_ctrlreg || priv->instance < 0)
 			dev_info(&pdev->dev, "control memory is not used for raminit\n");
 		else
 			priv->raminit = c_can_hw_raminit_ti;