VSPipe: fix several issues introduced with the argument changes
VSPipe: fix several issues introduced with the argument changes

Kamekameha/vapoursynth,vapoursynth/vapoursynth,Kamekameha/vapoursynth,vapoursynth/vapoursynth,vapoursynth/vapoursynth,Kamekameha/vapoursynth,Kamekameha/vapoursynth,vapoursynth/vapoursynth