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/vsock/csm/connection.rs

@@ -88,9 +88,8 @@ use std::time::{Duration, Instant};
 use super::super::defs::uapi;
 use super::super::packet::VsockPacket;
 use super::super::{Result as VsockResult, VsockChannel, VsockEpollListener, VsockError};
-use super::defs;
 use super::txbuf::TxBuf;
-use super::{ConnState, Error, PendingRx, PendingRxSet, Result};
+use super::{defs, ConnState, Error, PendingRx, PendingRxSet, Result};
 
 /// A self-managing connection object, that handles communication between a guest-side AF_VSOCK
 /// socket and a host-side `Read + Write + AsRawFd` stream.

virtio-devices/src/vsock/csm/txbuf.rs

@@ -5,8 +5,7 @@
 use std::io::Write;
 use std::num::Wrapping;
 
-use super::defs;
-use super::{Error, Result};
+use super::{defs, Error, Result};
 
 /// A simple ring-buffer implementation, used by vsock connections to buffer TX (guest -> host)
 /// data.  Memory for this buffer is allocated lazily, since buffering will only be needed when
@@ -144,9 +143,7 @@ impl TxBuf {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Error as IoError;
-    use std::io::ErrorKind;
-    use std::io::Result as IoResult;
+    use std::io::{Error as IoError, ErrorKind, Result as IoResult};
 
     use super::*;