regulator: tps6586x-regulator - fix value range checking for val

val is used as array index of ri->voltages.
Thus the valid value range should be 0 .. ri->desc.n_voltages - 1.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/tps6586x-regulator.c

@@ -133,7 +133,7 @@ static int tps6586x_ldo_get_voltage(struct regulator_dev *rdev)
 	mask = ((1 << ri->volt_nbits) - 1) << ri->volt_shift;
 	val = (val & mask) >> ri->volt_shift;
 
-	if (val > ri->desc.n_voltages)
+	if (val >= ri->desc.n_voltages)
 		BUG();
 
 	return ri->voltages[val] * 1000;