directwrite: fix error handling in font scanning
directwrite: fix error handling in font scanning

Fix that a single broken font could mess up the entire font scanning.

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