Invalid position setting in the GridFSSeekableDownloadStream with SeekOrigin.End

Invalid position setting in the GridFSSeekableDownloadStream
https://github.com/mongodb/mongo-csharp-driver/blob/master/src/MongoDB.Driver.GridFS/GridFSSeekableDownloadStream.cs#L128

Should be:
case SeekOrigin.End: newPosition = FileInfo.Length + offset; break;