iio: Fix documentation for iio_dev mlock

mlock *must* be used by core and drivers to protect access
to devices state changes.

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

include/linux/iio/iio.h

@@ -448,7 +448,7 @@ struct iio_buffer_setup_ops {
  * @buffer:		[DRIVER] any buffer present
  * @buffer_list:	[INTERN] list of all buffers currently attached
  * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
- * @mlock:		[INTERN] lock used to prevent simultaneous device state
+ * @mlock:		[DRIVER] lock used to prevent simultaneous device state
  *			changes
  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  * @masklength:		[INTERN] the length of the mask established from