omx: use list_is_linked

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8110>

src/gallium/frontends/omx/vid_enc_common.c

@@ -34,7 +34,7 @@ void enc_ReleaseTasks(struct list_head *head)
 {
    struct encode_task *i, *next;
 
-   if (!head || !head->next)
+   if (!head || !list_is_linked(head))
       return;
 
    LIST_FOR_EACH_ENTRY_SAFE(i, next, head, list) {