net: ethernet: ti: cpsw: add missing sanity check

Make sure to check for allocation failures before dereferencing a
NULL-pointer during probe.

Fixes: 649a1688 ("net: ethernet: ti: cpsw: create common struct to
hold shared driver data")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw.c

@@ -2588,6 +2588,9 @@ static int cpsw_probe(struct platform_device *pdev)
 	int irq;
 
 	cpsw = devm_kzalloc(&pdev->dev, sizeof(struct cpsw_common), GFP_KERNEL);
+	if (!cpsw)
+		return -ENOMEM;
+
 	cpsw->dev = &pdev->dev;
 
 	ndev = alloc_etherdev_mq(sizeof(struct cpsw_priv), CPSW_MAX_QUEUES);