message: storage: remove unnecessary debug_assert
  `self.offset + self.len != _offset` is legal when merge more regions.
  So the debug_assert is wrong
  Upper layer should ensure its validation.
diff: @@ -653,6 +653,8 @@ impl BlobIoVec {
  }
  /// A segment representing a continuous range for a blob IO operation.
  +/// It can span multiple chunks while the `offset` is where the user io starts
  +/// within the first chunk and `len` is the total user io length of these chunks.
  #[derive(Clone, Debug, Default)]
  pub struct BlobIoSegment {
  /// Start position of the range within the chunk
  @@ -669,7 +671,6 @@ impl BlobIoSegment {
  #[inline]
  pub fn append(&mut self, _offset: u32, len: u32) {
  - debug_assert!(self.offset + self.len == _offset);
  debug_assert!(_offset.checked_add(len).is_some());
  debug_assert!((self.offset + self.len).checked_add(len).is_some());
  