block: Derive Debug on RawFileDiskAio

Add #[derive(Debug)] to RawFileDiskAio. This is required
by the new disk_file traits which have Send + Debug bounds.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

Author: russell-islam

block/src/raw_async_aio.rs

@@ -19,6 +19,7 @@ use crate::async_io::{
 };
 use crate::{DiskTopology, SECTOR_SIZE, probe_sparse_support, query_device_size};
 
+#[derive(Debug)]
 pub struct RawFileDiskAio {
     file: File,
 }