virtio-devices: Fix beta clippy issue

error: use of a fallible conversion when an infallible one could be used
Error:    --> virtio-devices/src/vhost_user/vu_common_ctrl.rs:206:51
    |
206 |             let actual_size: usize = queue.size().try_into().unwrap();
    |                                                   ^^^^^^^^^^^^^^^^^^^ help: use: `into()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fallible_conversions
    = note: `-D clippy::unnecessary-fallible-conversions` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::unnecessary_fallible_conversions)]`

error: could not compile `virtio-devices` (lib) due to previous error
Error: warning: build failed, waiting for other jobs to finish...
error: could not compile `virtio-devices` (lib test) due to previous error
Error: The process '/home/runner/.cargo/bin/cargo' failed with exit code 101

Signed-off-by: Bo Chen <[email protected]>

virtio-devices/src/vhost_user/vu_common_ctrl.rs

@@ -7,7 +7,6 @@ use crate::{
     get_host_address_range, GuestMemoryMmap, GuestRegionMmap, MmapRegion, VirtioInterrupt,
     VirtioInterruptType,
 };
-use std::convert::TryInto;
 use std::ffi;
 use std::fs::File;
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
@@ -203,7 +202,7 @@ impl VhostUserHandle {
 
         let mut vrings_info = Vec::new();
         for (queue_index, queue, queue_evt) in queues.iter() {
-            let actual_size: usize = queue.size().try_into().unwrap();
+            let actual_size: usize = queue.size().into();
 
             let config_data = VringConfigData {
                 queue_max_size: queue.max_size(),