block, pci, rate_limiter, vm-allocator: drop legacy numeric constants

Signed-off-by: Wei Liu <liuwe@microsoft.com>

pci/src/bus.rs

@@ -409,7 +409,7 @@ impl BusDevice for PciConfigMmio {
         // Only allow reads to the register boundary.
         let start = offset as usize % 4;
         let end = start + data.len();
-        if end > 4 || offset > u64::from(u32::max_value()) {
+        if end > 4 || offset > u64::from(u32::MAX) {
             for d in data {
                 *d = 0xff;
             }
@@ -423,7 +423,7 @@ impl BusDevice for PciConfigMmio {
     }
 
     fn write(&mut self, _base: u64, offset: u64, data: &[u8]) -> Option<Arc<Barrier>> {
-        if offset > u64::from(u32::max_value()) {
+        if offset > u64::from(u32::MAX) {
             return None;
         }
         self.config_space_write(offset as u32, offset % 4, data);

pci/src/configuration.rs

@@ -743,7 +743,7 @@ impl PciConfiguration {
             .ok_or(Error::BarAddressInvalid(config.addr, config.size))?;
         match config.region_type {
             PciBarRegionType::Memory32BitRegion | PciBarRegionType::IoRegion => {
-                if end_addr > u64::from(u32::max_value()) {
+                if end_addr > u64::from(u32::MAX) {
                     return Err(Error::BarAddressInvalid(config.addr, config.size));
                 }
 
@@ -814,7 +814,7 @@ impl PciConfiguration {
             .checked_add(config.size - 1)
             .ok_or(Error::RomBarAddressInvalid(config.addr, config.size))?;
 
-        if end_addr > u64::from(u32::max_value()) {
+        if end_addr > u64::from(u32::MAX) {
             return Err(Error::RomBarAddressInvalid(config.addr, config.size));
         }
 

pci/src/vfio_user.rs

@@ -11,7 +11,6 @@ use std::any::Any;
 use std::os::unix::prelude::AsRawFd;
 use std::ptr::null_mut;
 use std::sync::{Arc, Barrier, Mutex};
-use std::u32;
 use thiserror::Error;
 use vfio_bindings::bindings::vfio::*;
 use vfio_ioctls::VfioIrq;