i2c: arb-gpio-challenge: use of_get_i2c_adapter_by_node interface

This change is needed to properly lock I2C parent bus driver.

Prior to this change i2c_put_adapter() is misused, which may lead
to an overflow over zero of I2C bus driver user counter.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/muxes/i2c-arb-gpio-challenge.c

@@ -196,7 +196,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 		dev_err(dev, "Cannot parse i2c-parent\n");
 		return -EINVAL;
 	}
-	arb->parent = of_find_i2c_adapter_by_node(parent_np);
+	arb->parent = of_get_i2c_adapter_by_node(parent_np);
 	if (!arb->parent) {
 		dev_err(dev, "Cannot find parent bus\n");
 		return -EPROBE_DEFER;