ivi-shell: Remove the compositor destory listener from list during de-init

During de-init ensure removal of compositor destroy notification
from list. Otherwise a dongling pointer is left behind which will
affect other plugins.

Signed-off-by: Harsha M M <harsha.manjulamallikarjun@in.bosch.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

ivi-shell/ivi-shell.c

@@ -358,6 +358,8 @@ shell_destroy(struct wl_listener *listener, void *data)
 		container_of(listener, struct ivi_shell, destroy_listener);
 	struct ivi_shell_surface *ivisurf, *next;
 
+	wl_list_remove(&shell->destroy_listener.link);
+
 	text_backend_destroy(shell->text_backend);
 	input_panel_destroy(shell);