message: rafs: print more errors when seek fails
  It is friendly when analyze problems
diff: @@ -85,18 +85,29 @@ impl dyn RafsIoWrite {
  impl dyn RafsIoRead {
  pub fn seek_to_next_aligned(&mut self, last_read_len: usize) -> Result<u64> {
  // Seek should not fail otherwise rafs goes insane.
  - self.seek(SeekFrom::Current(
  - (align_to_rafs(last_read_len) - last_read_len) as i64,
  - ))
  + let offset = (align_to_rafs(last_read_len) - last_read_len) as i64;
  + self.seek(SeekFrom::Current(offset)).map_err(|e| {
  + error!("Seeking to offset {} from current fails, {}", offset, e);
  + e
  + })
  }
  pub fn seek_plus_offset(&mut self, plus_offset: i64) -> Result<u64> {
  // Seek should not fail otherwise rafs goes insane.
  - self.seek(SeekFrom::Current(plus_offset))
  + self.seek(SeekFrom::Current(plus_offset)).map_err(|e| {
  + error!(
  + "Seeking to offset {} from current fails, {}",
  + plus_offset, e
  + );
  + e
  + })
  }
  pub fn seek_to_offset(&mut self, offset: u64) -> Result<u64> {
  - self.seek(SeekFrom::Start(offset))
  + self.seek(SeekFrom::Start(offset)).map_err(|e| {
  + error!("Seeking to offset {} from start fails, {}", offset, e);
  + e
  + })
  }
  pub fn from_file(path: impl AsRef<Path>) -> RafsResult<RafsIoReader> {
  