power: supply: max17042_battery: Improve accuracy of current_now and current_avg readings

Dividing 1562500 by r_sns value usually doesn't result in an integer.
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/max17042_battery.c

@@ -395,8 +395,8 @@ static int max17042_get_property(struct power_supply *psy,
 			if (ret < 0)
 				return ret;
 
-			val->intval = sign_extend32(data, 15);
-			val->intval *= 1562500 / chip->pdata->r_sns;
+			data64 = sign_extend64(data, 15) * 1562500ll;
+			val->intval = div_s64(data64, chip->pdata->r_sns);
 		} else {
 			return -EINVAL;
 		}
@@ -407,8 +407,8 @@ static int max17042_get_property(struct power_supply *psy,
 			if (ret < 0)
 				return ret;
 
-			val->intval = sign_extend32(data, 15);
-			val->intval *= 1562500 / chip->pdata->r_sns;
+			data64 = sign_extend64(data, 15) * 1562500ll;
+			val->intval = div_s64(data64, chip->pdata->r_sns);
 		} else {
 			return -EINVAL;
 		}