message: rafs: remove RafsInode::walk_chunks()
  There's no user of RafsInode::walk_chunks(), so remove it.
diff: @@ -224,18 +224,6 @@ pub trait RafsInode: Any {
  /// Regular: get chunk info object by chunk index, chunk index starts from 0.
  fn get_chunk_info(&self, idx: u32) -> Result<Arc<dyn BlobChunkInfo>>;
  - /// Regular: walk/enumerate all data chunks.
  - fn walk_chunks(
  - &self,
  - cb: &mut dyn FnMut(&dyn BlobChunkInfo) -> anyhow::Result<()>,
  - ) -> anyhow::Result<()> {
  - let chunk_count = self.get_chunk_count();
  - for i in 0..chunk_count {
  - cb(self.get_chunk_info(i)?.as_ref())?;
  - }
  - Ok(())
  - }
  -
  fn as_any(&self) -> &dyn Any;
  }
  