hwmon: (ltc2992) Put fwnode in error case during ->probe()

In each iteration fwnode_for_each_available_child_node() bumps a reference
counting of a loop variable followed by dropping in on a next iteration,

Since in error case the loop is broken, we have to drop a reference count
by ourselves. Do it for port_fwnode in error case during ->probe().

Fixes: b0bd407 ("hwmon: (ltc2992) Add support")
Cc: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210510100136.3303142-1-andy.shevchenko@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/ltc2992.c

@@ -900,11 +900,15 @@ static int ltc2992_parse_dt(struct ltc2992_state *st)
 
 	fwnode_for_each_available_child_node(fwnode, child) {
 		ret = fwnode_property_read_u32(child, "reg", &addr);
-		if (ret < 0)
+		if (ret < 0) {
+			fwnode_handle_put(child);
 			return ret;
+		}
 
-		if (addr > 1)
+		if (addr > 1) {
+			fwnode_handle_put(child);
 			return -EINVAL;
+		}
 
 		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
 		if (!ret)