mfd: max77620: Fix refcount leak in max77620_initialise_fps

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: 327156c5 ("mfd: max77620: Add core driver for MAX77620/MAX20024")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220601043222.64441-1-linmq006@gmail.com

drivers/mfd/max77620.c

@@ -419,9 +419,11 @@ static int max77620_initialise_fps(struct max77620_chip *chip)
 		ret = max77620_config_fps(chip, fps_child);
 		if (ret < 0) {
 			of_node_put(fps_child);
+			of_node_put(fps_np);
 			return ret;
 		}
 	}
+	of_node_put(fps_np);
 
 	config = chip->enable_global_lpm ? MAX77620_ONOFFCNFG2_SLP_LPM_MSK : 0;
 	ret = regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG2,