extcon-max8997: remove usage of ret in max8997_muic_handle_charger_type_detach

actually we can do returns with error or success with out ret in this function,
so remove the ret variable, and reduce a very little (4byte) space on stack of this function
Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/extcon/extcon-max8997.c

@@ -271,8 +271,6 @@ static int max8997_muic_handle_adc(struct max8997_muic_info *info, int adc)
 static int max8997_muic_handle_charger_type_detach(
 				struct max8997_muic_info *info)
 {
-	int ret = 0;
-
 	switch (info->pre_charger_type) {
 	case MAX8997_CHARGER_TYPE_USB:
 		extcon_set_cable_state(info->edev, "USB", false);
@@ -290,11 +288,11 @@ static int max8997_muic_handle_charger_type_detach(
 		extcon_set_cable_state(info->edev, "Fast-charger", false);
 		break;
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 		break;
 	}
 
-	return ret;
+	return 0;
 }
 
 static int max8997_muic_handle_charger_type(struct max8997_muic_info *info,