fontselect: add const
fontselect: add const

torque/libass,stps/libass,xbmc/libass,mwgoldsmith/libass,stps/libass,sanyaade-g2g-repos/libass,mwgoldsmith/libass,ShiftMediaProject/libass,sanyaade-g2g-repos/libass,sanyaade-g2g-repos/libass,astiob/libass,MrSmile/libass,torque/libass,libass/libass,Akemi/libass,torque/libass,Akemi/libass,astiob/libass,MrSmile/libass,libass/libass,xbmc/libass,ShiftMediaProject/libass,grigorig/libass,stps/libass,Akemi/libass,mwgoldsmith/libass,grigorig/libass