remoteproc: imx_rproc: fix return value check in imx_rproc_addr_init()

In case of error, the function devm_ioremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.
Reviewed-by: NOleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/imx_rproc.c

@@ -269,10 +269,9 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
 
 		priv->mem[b].cpu_addr = devm_ioremap(&pdev->dev,
 						     att->sa, att->size);
-		if (IS_ERR(priv->mem[b].cpu_addr)) {
+		if (!priv->mem[b].cpu_addr) {
 			dev_err(dev, "devm_ioremap_resource failed\n");
-			err = PTR_ERR(priv->mem[b].cpu_addr);
-			return err;
+			return -ENOMEM;
 		}
 		priv->mem[b].sys_addr = att->sa;
 		priv->mem[b].size = att->size;