ffmpeg_wrapper_path_to_vhook returns bool instead of string

The function ffmpeg_wrapper_path_to_vhook returns a bool variabile rather than a string with the path to the vhook. This prevents watermarking to work.

Instead of this:

function ffmpeg_wrapper_path_to_vhook($name) {
  if ($path = file_exists(variable_get('ffmpeg_wrapper_vhook', '/usr/local/lib/vhook/') . $name)) {
    return $path;
  }
}

it should be like this:

function ffmpeg_wrapper_path_to_vhook($name) {
  $path = variable_get('ffmpeg_wrapper_vhook', '/usr/local/lib/vhook/') . $name;
  if (file_exists($path)) {
    return $path;
  }
}