media player: fix a bunch of memory leaks when interating track descriptions (closes #15403)
media player: fix a bunch of memory leaks when interating track descriptions (closes #15403)

CollabraMusic/VLCKit,siuying/VLCKit,CollabraMusic/VLCKit,CollabraMusic/VLCKit,siuying/VLCKit,simon1984/test,kamcord/VLCKit,waterskier2007/VLCKit,kamcord/VLCKit,siuying/VLCKit,kamcord/VLCKit,waterskier2007/VLCKit,simon1984/test,simon1984/test,waterskier2007/VLCKit