message: Collapse else-if blocks
  Fixes clippy::collapsible_else_if
diff: @@ -150,8 +150,7 @@ impl DescrRing {
  0,
  )
  }
  - } else {
  - if len > 1 {
  + } else if len > 1 {
  let next_index = {
  let (desc, _) = desc_lst[desc_cnt + 1];
  desc.id.as_ref().unwrap().0 - 1
  @@ -172,8 +171,7 @@ impl DescrRing {
  next_index,
  )
  }
  - } else {
  - if is_write {
  + } else if is_write {
  Descriptor::new(
  paging::virt_to_phys(VirtAddr::from(desc.ptr as u64)).into(),
  desc.len as u32,
  @@ -187,8 +185,6 @@ impl DescrRing {
  0,
  0,
  )
  - }
  - }
  };
  self.descr_table.raw[write_indx] = descriptor;
  