iio: adc: qcom-vadc-common: simplify qcom_vadc_map_voltage_temp

All volt-temp tables here are sorted in descending order. There is no
need to accout for (unused) ascending table sorting case, so simplify
the conversion function.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20201204025509.1075506-11-dmitry.baryshkov@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/qcom-vadc-common.c

@@ -346,38 +346,19 @@ static struct qcom_adc5_scale_type scale_adc5_fn[] = {
 static int qcom_vadc_map_voltage_temp(const struct vadc_map_pt *pts,
 				      u32 tablesize, s32 input, int *output)
 {
-	bool descending = 1;
 	u32 i = 0;
 
 	if (!pts)
 		return -EINVAL;
 
-	/* Check if table is descending or ascending */
-	if (tablesize > 1) {
-		if (pts[0].x < pts[1].x)
-			descending = 0;
-	}
-
-	while (i < tablesize) {
-		if ((descending) && (pts[i].x < input)) {
-			/* table entry is less than measured*/
-			 /* value and table is descending, stop */
-			break;
-		} else if ((!descending) &&
-				(pts[i].x > input)) {
-			/* table entry is greater than measured*/
-			/*value and table is ascending, stop */
-			break;
-		}
+	while (i < tablesize && pts[i].x > input)
 		i++;
-	}
 
 	if (i == 0) {
 		*output = pts[0].y;
 	} else if (i == tablesize) {
 		*output = pts[tablesize - 1].y;
 	} else {
-		/* result is between search_index and search_index-1 */
 		/* interpolate linearly */
 		*output = fixp_linear_interpolate(pts[i - 1].x, pts[i - 1].y,
 						  pts[i].x, pts[i].y,