libcamera: camera_manager: Document the CameraManager destructor

The destructor stops the camera manager if it is running. This is at the
moment an implementation detail, but makes sense to guarantee in the
API. Document it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

src/libcamera/camera_manager.cpp

@@ -269,6 +269,11 @@ CameraManager::CameraManager()
 	self_ = this;
 }
 
+/**
+ * \brief Destroy the camera manager
+ *
+ * Destroying the camera manager stops it if it is currently running.
+ */
 CameraManager::~CameraManager()
 {
 	stop();