Add few more bool returns to libvlc.

Didn't notice them first time.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

include/vlc/libvlc_media.h

@@ -378,6 +378,8 @@ LIBVLC_API libvlc_state_t libvlc_media_get_state(
  * \param p_stats: structure that contain the statistics about the media
  *                 (this structure must be allocated by the caller)
  * \return true if the statistics are available, false otherwise
+ *
+ * \libvlc_return_bool
  */
 LIBVLC_API int libvlc_media_get_stats( libvlc_media_t *p_md,
                                            libvlc_media_stats_t *p_stats );

include/vlc/libvlc_media_list_player.h

@@ -140,6 +140,8 @@ void libvlc_media_list_player_pause(libvlc_media_list_player_t * p_mlp);
  *
  * \param p_mlp media list player instance
  * \return true for playing and false for not playing
+ *
+ * \libvlc_return_bool
  */
 LIBVLC_API int
     libvlc_media_list_player_is_playing( libvlc_media_list_player_t * p_mlp );