net: ethernet: ti: fix some return value check of cpsw_ale_create()

cpsw_ale_create() can return both NULL and PTR_ERR(), but all of
the caller only check NULL for error handling. This patch convert
it to only return PTR_ERR() in all error cases, and the caller using
IS_ERR() instead of NULL test.

Fixes: 4b41d343 ("net: ethernet: ti: cpsw: allow untagged traffic on host port")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw_ale.c

@@ -955,7 +955,7 @@ struct cpsw_ale *cpsw_ale_create(struct cpsw_ale_params *params)
 
 	ale = devm_kzalloc(params->dev, sizeof(*ale), GFP_KERNEL);
 	if (!ale)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	ale->p0_untag_vid_mask =
 		devm_kmalloc_array(params->dev, BITS_TO_LONGS(VLAN_N_VID),

drivers/net/ethernet/ti/cpsw_priv.c

@@ -490,9 +490,9 @@ int cpsw_init_common(struct cpsw_common *cpsw, void __iomem *ss_regs,
 	ale_params.ale_ports		= CPSW_ALE_PORTS_NUM;
 
 	cpsw->ale = cpsw_ale_create(&ale_params);
-	if (!cpsw->ale) {
+	if (IS_ERR(cpsw->ale)) {
 		dev_err(dev, "error initializing ale engine\n");
-		return -ENODEV;
+		return PTR_ERR(cpsw->ale);
 	}
 
 	dma_params.dev		= dev;

drivers/net/ethernet/ti/netcp_ethss.c

@@ -3704,9 +3704,9 @@ static int gbe_probe(struct netcp_device *netcp_device, struct device *dev,
 		ale_params.nu_switch_ale = true;
 	}
 	gbe_dev->ale = cpsw_ale_create(&ale_params);
-	if (!gbe_dev->ale) {
+	if (IS_ERR(gbe_dev->ale)) {
 		dev_err(gbe_dev->dev, "error initializing ale engine\n");
-		ret = -ENODEV;
+		ret = PTR_ERR(gbe_dev->ale);
 		goto free_sec_ports;
 	} else {
 		dev_dbg(gbe_dev->dev, "Created a gbe ale engine\n");