Latest snapshot bug fix (int pandavfs_write func)

Compiling or Editing the Panda Source
1

i found a small bug when compiling from snapshot on linux in panda/src/movies/ffmpegVirtualFile.cxx
Here is the solution - fix for ffmpeg bug
http://pastebin.com/0KFFgTbp

2

Thanks, I checked in something that ought to fix it.