power: supply: max8997: Improve a size determination in probe

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/power/supply/max8997_charger.c

@@ -146,8 +146,7 @@ static int max8997_battery_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	charger = devm_kzalloc(&pdev->dev, sizeof(struct charger_data),
-				GFP_KERNEL);
+	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 	if (!charger)
 		return -ENOMEM;