misc: Further improve imports styling

By introducing `imports_granularity="Module"` format strategy,
effectively groups imports from the same module into one line or block,
improving maintainability and readability.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

virtio-devices/src/vdpa.rs

@@ -3,24 +3,19 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-use std::{
-    collections::BTreeMap,
-    io, result,
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        Arc, Mutex,
-    },
-};
+use std::collections::BTreeMap;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+use std::{io, result};
 
 use anyhow::anyhow;
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
-use vhost::{
-    vdpa::{VhostVdpa, VhostVdpaIovaRange},
-    vhost_kern::VhostKernFeatures,
-    vhost_kern::{vdpa::VhostKernVdpa, vhost_binding::VHOST_BACKEND_F_SUSPEND},
-    VhostBackend, VringConfigData,
-};
+use vhost::vdpa::{VhostVdpa, VhostVdpaIovaRange};
+use vhost::vhost_kern::vdpa::VhostKernVdpa;
+use vhost::vhost_kern::vhost_binding::VHOST_BACKEND_F_SUSPEND;
+use vhost::vhost_kern::VhostKernFeatures;
+use vhost::{VhostBackend, VringConfigData};
 use virtio_queue::{Descriptor, Queue, QueueT};
 use vm_device::dma_mapping::ExternalDmaMapping;
 use vm_memory::{GuestAddress, GuestAddressSpace, GuestMemory, GuestMemoryAtomic};