regulator: max8997: remove useless code

fix unreachable code.
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/max8997.c

@@ -267,7 +267,6 @@ static int max8997_get_enable_register(struct regulator_dev *rdev,
 	default:
 		/* Not controllable or not exists */
 		return -EINVAL;
-		break;
 	}
 
 	return 0;