misc: Remove redundant "use" imports

With the nightly toolchain (2024-02-18) cargo check will flag up
redundant imports either because they are pulled in by the prelude on
earlier match.

Remove those redundant imports.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>

block/src/vhd.rs

@@ -3,7 +3,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use crate::{read_aligned_block_size, DiskTopology};
-use std::convert::TryInto;
 use std::fs::File;
 use std::io::{Seek, SeekFrom};