regulator: ab8500 - fix off-by-one value range checking for selector

selector is used as array index of info->supported_voltages
Thus the valid value range should be 0 .. info->voltages_len -1

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@openource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/ab8500.c

@@ -157,7 +157,7 @@ static int ab8500_list_voltage(struct regulator_dev *rdev, unsigned selector)
 	if (info->fixed_uV)
 		return info->fixed_uV;
 
-	if (selector > info->voltages_len)
+	if (selector >= info->voltages_len)
 		return -EINVAL;
 
 	return info->supported_voltages[selector];