fixed return code from unprepare capture during EOS exit
fixed return code from unprepare capture during EOS exit

https://github.com/jim-easterbrook/python-gphoto2/issues/128
https://github.com/gphoto/libgphoto2/issues/352

gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2