net: stmicro: replace kzalloc with devm_kzalloc

The axi variable was not being freed upon device removal.
With devm_kzalloc it ensures that it is properly freed.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

@@ -108,7 +108,7 @@ static struct stmmac_axi *stmmac_axi_setup(struct platform_device *pdev)
 	if (!np)
 		return NULL;
 
-	axi = kzalloc(sizeof(*axi), GFP_KERNEL);
+	axi = devm_kzalloc(&pdev->dev, sizeof(*axi), GFP_KERNEL);
 	if (!axi) {
 		of_node_put(np);
 		return ERR_PTR(-ENOMEM);