net: ll_temac: check the return value of devm_kmalloc()

devm_kmalloc() returns a pointer to allocated memory on success, NULL
on failure. While lp->indirect_lock is allocated by devm_kmalloc()
without proper check. It is better to check the value of it to
prevent potential wrong memory access.

Fixes: f14f5c11 ("net: ll_temac: Support indirect_mutex share within TEMAC IP")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/ll_temac_main.c

@@ -1433,6 +1433,8 @@ static int temac_probe(struct platform_device *pdev)
 		lp->indirect_lock = devm_kmalloc(&pdev->dev,
 						 sizeof(*lp->indirect_lock),
 						 GFP_KERNEL);
+		if (!lp->indirect_lock)
+			return -ENOMEM;
 		spin_lock_init(lp->indirect_lock);
 	}