iio:buffer:iio_push_to_buffers_with_timestamp fix kernel-doc.

Wrong start of kernel doc comment /* -> /**
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

include/linux/iio/buffer.h

@@ -163,7 +163,7 @@ void iio_buffer_init(struct iio_buffer *buffer);
 
 int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data);
 
-/*
+/**
  * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers
  * @indio_dev:		iio_dev structure for device.
  * @data:		sample data