net: wan: fix error return code of uhdlc_init()

When priv->rx_skbuff or priv->tx_skbuff is NULL, no error return code of
uhdlc_init() is assigned.
To fix this bug, ret is assigned with -ENOMEM in these cases.
Reported-by: NTOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/wan/fsl_ucc_hdlc.c

@@ -204,14 +204,18 @@ static int uhdlc_init(struct ucc_hdlc_private *priv)
 	priv->rx_skbuff = kcalloc(priv->rx_ring_size,
 				  sizeof(*priv->rx_skbuff),
 				  GFP_KERNEL);
-	if (!priv->rx_skbuff)
+	if (!priv->rx_skbuff) {
+		ret = -ENOMEM;
 		goto free_ucc_pram;
+	}
 
 	priv->tx_skbuff = kcalloc(priv->tx_ring_size,
 				  sizeof(*priv->tx_skbuff),
 				  GFP_KERNEL);
-	if (!priv->tx_skbuff)
+	if (!priv->tx_skbuff) {
+		ret = -ENOMEM;
 		goto free_rx_skbuff;
+	}
 
 	priv->skb_curtx = 0;
 	priv->skb_dirtytx = 0;