[mutter] backends/x11: Fix device hierarchy event handling for x11 backend

[Marge Bot <marge-bot src gnome org>]

commit b353b9751270ed44d6d1d5d8c7be2796e92dd368
Author: Suryashankar Das <suryashankardas 2002 gmail com>
Date:   Wed Mar 10 15:30:05 2021 +0530

    backends/x11: Fix device hierarchy event handling for x11 backend
    
    This commit adds the events created in the function
    `meta_seat_x11_notify_devices` to the clutter events queue, which
    are currently only added to the stage queue making the events not
    being picked up by the `clutter_seat_handle_event_post` function.
    This results in devices not getting added to the device-list of
    `MetaInputSettings`.
    
    Fixes the bug in which mouse and touchpad settings are not working in
    the settings app during x11 session.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1767>

 src/backends/x11/meta-seat-x11.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/backends/x11/meta-seat-x11.c b/src/backends/x11/meta-seat-x11.c
index 1e0d19120f..7ed00307f4 100644
--- a/src/backends/x11/meta-seat-x11.c
+++ b/src/backends/x11/meta-seat-x11.c
@@ -1346,7 +1346,8 @@ meta_seat_x11_notify_devices (MetaSeatX11  *seat_x11,
       event = clutter_event_new (CLUTTER_DEVICE_ADDED);
       clutter_event_set_device (event, device);
       clutter_event_set_stage (event, stage);
-      clutter_do_event (event);
+      clutter_event_put (event);
+      clutter_event_free (event);
     }
 }