iio: fix drivers that check buffer->scan_mask

If the in-kernel push interface is used we may have a different masks
on the device buffer and the kernel buffer and in this case the device
should generate data for the reunion of the buffers, which is
available at indio_dev->active_scan_mask.

Compiled tested only except for bmc150-accel which was tested at
runtime with the hardware.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/proximity/sx9500.c b/drivers/iio/proximity/sx9500.c
index 74dff4e..89fca3a 100644
--- a/drivers/iio/proximity/sx9500.c
+++ b/drivers/iio/proximity/sx9500.c
@@ -494,7 +494,7 @@
 
 	mutex_lock(&data->mutex);
 
-	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
 		ret = sx9500_read_proximity(data, &indio_dev->channels[bit],
 					    &val);