Add to the docs the fact that is only safe to iterate
GstCollectPad's data list inside the collected callback.
Fixes #610366
* @data: #GList of #GstCollectData managed by this #GstCollectPads.
*
* Collectpads object.
- * Note that @data doesn't contain the complete #GstCollectData list
- * at all times and should not be used for iterating them.
+ * Note that @data is only reliable for iterating the list of #GstCollectData
+ * when inside the #GstCollectPadsFunction callback.
*/
struct _GstCollectPads {
GstObject object;