interconnect: imx: Fix return value check in imx_icc_node_init_qos()

In case of error, the function of_parse_phandle() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.

Fixes: f0d80485 ("interconnect: Add imx core driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Link: https://lore.kernel.org/r/20200509030214.14435-1-weiyongjun1@huawei.comSigned-off-by: Georgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/imx/imx.c

@@ -90,10 +90,10 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
 			node->name, node->id);
 	} else {
 		dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
-		if (IS_ERR(dn)) {
-			dev_warn(dev, "Failed to parse %s: %ld\n",
-				 adj->phandle_name, PTR_ERR(dn));
-			return PTR_ERR(dn);
+		if (!dn) {
+			dev_warn(dev, "Failed to parse %s\n",
+				 adj->phandle_name);
+			return -ENODEV;
 		}
 		/* Allow scaling to be disabled on a per-node basis */
 		if (!dn || !of_device_is_available(dn)) {