block_util: Port synchronous RAW file to AsyncIo trait

Based on the synchronous RAW file implementation present in the qcow
crate, we created a new raw_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.

The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

block_util/src/lib.rs

@@ -15,6 +15,7 @@ extern crate serde_derive;
 
 pub mod async_io;
 pub mod raw_async;
+pub mod raw_sync;
 
 use crate::async_io::{AsyncIo, AsyncIoError};
 #[cfg(feature = "io_uring")]