input/item: fix too small psz_scheme array
input/item: fix too small psz_scheme array

Indeed, "qtsound" needs a size of 8.
Use a pointer instead of a fixed size array.

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc