Use libinput_event_destroy/xkb_*_unref

Also sneak in a missing drmModeFreePlaneResources

backend/drm/drm.c

@@ -104,6 +104,7 @@ static bool init_planes(struct wlr_backend_state *drm) {
 	drm->primary_planes = drm->overlay_planes + drm->num_overlay_planes;
 	drm->cursor_planes = drm->primary_planes + drm->num_primary_planes;
 
+	drmModeFreePlaneResources(plane_res);
 	return true;
 
 error_planes:

backend/libinput/backend.c

@@ -33,6 +33,7 @@ static int wlr_libinput_readable(int fd, uint32_t mask, void *_state) {
 	struct libinput_event *event;
 	while ((event = libinput_get_event(state->libinput))) {
 		wlr_libinput_event(state, event);
+		libinput_event_destroy(event);
 	}
 	return 0;
 }

examples/shared.c

@@ -311,6 +311,8 @@ static void keyboard_remove(struct wlr_input_device *device, struct compositor_s
 	if (!kbstate) {
 		return;
 	}
+	xkb_state_unref(kbstate->xkb_state);
+	xkb_map_unref(kbstate->keymap);
 	wl_list_remove(&kbstate->link);
 	wl_list_remove(&kbstate->key.link);
 	free(kbstate);