message: rafs: fix gzip decompress
  flate2::read::GzDecoder only decode part of the gzip stream. Change
  to use flate2::bufread::GzDecoder instead, which provides read_exact()
  method.
diff: @@ -8,7 +8,7 @@ use std::io::{Error, Result};
  use std::io::{Read, Write};
  use std::str::FromStr;
  -use flate2::read::GzDecoder;
  +use flate2::bufread::GzDecoder;
  use flate2::write::GzEncoder;
  use flate2::Compression;
  @@ -88,7 +88,11 @@ pub fn decompress(src: &[u8], dst: &mut [u8], algorithm: Algorithm) -> Result<us
  match algorithm {
  Algorithm::None => Ok(dst.len()),
  Algorithm::LZ4Block => lz4_decompress(src, dst),
  - Algorithm::GZip => GzDecoder::new(src).read(dst),
  + Algorithm::GZip => {
  + let mut gz = GzDecoder::new(src);
  + gz.read_exact(dst)?;
  + Ok(dst.len())
  + }
  }
  }
  