docs: iio: fix directory naming

This directory is a, well, directory, not a file.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-3-luca@lucaceresoli.netSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/driver-api/iio/buffers.rst

@@ -28,7 +28,7 @@ IIO buffer setup
 The meta information associated with a channel reading placed in a buffer is
 called a scan element. The important bits configuring scan elements are
 exposed to userspace applications via the
-:file:`/sys/bus/iio/iio:device{X}/scan_elements/*` directory. This file contains
+:file:`/sys/bus/iio/iio:device{X}/scan_elements/` directory. This directory contains
 attributes of the following form:
 
 * :file:`enable`, used for enabling a channel. If and only if its attribute