iio: gyro: adis16260: replace mlock with ADIS lib's state_lock

This change uses the ADIS library's state_lock to protect the state of the
`max_speed_hz` change that is done during the set of the sampling
frequency.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/gyro/adis16260.c

@@ -293,7 +293,7 @@ static int adis16260_write_raw(struct iio_dev *indio_dev,
 		addr = adis16260_addresses[chan->scan_index][1];
 		return adis_write_reg_16(adis, addr, val);
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		mutex_lock(&indio_dev->mlock);
+		mutex_lock(&adis->state_lock);
 		if (spi_get_device_id(adis->spi)->driver_data)
 			t = 256 / val;
 		else
@@ -308,9 +308,9 @@ static int adis16260_write_raw(struct iio_dev *indio_dev,
 			adis->spi->max_speed_hz = ADIS16260_SPI_SLOW;
 		else
 			adis->spi->max_speed_hz = ADIS16260_SPI_FAST;
-		ret = adis_write_reg_8(adis, ADIS16260_SMPL_PRD, t);
+		ret = __adis_write_reg_8(adis, ADIS16260_SMPL_PRD, t);
 
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&adis->state_lock);
 		return ret;
 	}
 	return -EINVAL;