iio: mxs-lradc: Remove useless check in read_raw

The removed check in the read_raw implementation was always true,
therefore remove it. This also fixes a bug, by closely inspecting
the code, one can notice the iio_validate_scan_mask_onehot() will
always return 1 and therefore the subsequent condition will always
succeed, therefore making the mxs_lradc_read_raw() function always
return -EINVAL; .
Signed-off-by: Marek Vasut <marex@denx.de>
Tested-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/mxs-lradc.c

@@ -234,7 +234,6 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
 {
 	struct mxs_lradc *lradc = iio_priv(iio_dev);
 	int ret;
-	unsigned long mask;
 
 	if (m != IIO_CHAN_INFO_RAW)
 		return -EINVAL;
@@ -243,12 +242,6 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
 	if (chan->channel > LRADC_MAX_TOTAL_CHANS)
 		return -EINVAL;
 
-	/* Validate the channel if it doesn't intersect with reserved chans. */
-	bitmap_set(&mask, chan->channel, 1);
-	ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
-	if (ret)
-		return -EINVAL;
-
 	/*
 	 * See if there is no buffered operation in progess. If there is, simply
 	 * bail out. This can be improved to support both buffered and raw IO at