net: ethernet: arc: Fix a potential memory leak if an optional regulator is deferred

BugLink: http://bugs.launchpad.net/bugs/1764999

[ Upstream commit 00777fac ]

If the optional regulator is deferred, we must release some resources.
They will be re-allocated when the probe function will be called again.

Fixes: 6eacf311 ("ethernet: arc: Add support for Rockchip SoC layer device tree bindings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/arc/emac_rockchip.c

@@ -150,8 +150,10 @@ static int emac_rockchip_probe(struct platform_device *pdev)
 	/* Optional regulator for PHY */
 	priv->regulator = devm_regulator_get_optional(dev, "phy");
 	if (IS_ERR(priv->regulator)) {
-		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER) {
+			err = -EPROBE_DEFER;
+			goto out_clk_disable;
+		}
 		dev_err(dev, "no regulator found\n");
 		priv->regulator = NULL;
 	}