regulator: Ensure val is initialised in 88pm8607 choose_voltage()

If we fall through it means that we hit an unknown regulator/chip
combination so set -ENOENT as an explicit flag (the return code
is only used internally).

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/88pm8607.c

@@ -170,7 +170,8 @@ static int choose_voltage(struct regulator_dev *rdev, int min_uV, int max_uV)
 {
 	struct pm8607_regulator_info *info = rdev_get_drvdata(rdev);
 	uint8_t chip_id = info->chip->chip_id;
-	int val, ret;
+	int val = -ENOENT;
+	int ret;
 
 	switch (info->desc.id) {
 	case PM8607_ID_BUCK1: