Fix a couple of warnings

src/percpu.rs

@@ -19,7 +19,7 @@ use crate::{
     cpu_set::{LogicalCpuId, MAX_CPU_COUNT},
     cpu_stats::{CpuStats, CpuStatsData},
     ptrace::Session,
-    sync::{CleanLockToken, LockToken, RwLock, L0, L1},
+    sync::{CleanLockToken, LockToken, RwLock, L1},
     syscall::debug::SyscallDebugInfo,
 };
 

src/scheme/sys/block.rs

@@ -1,7 +1,7 @@
 use alloc::{string::String, vec::Vec};
 use core::fmt::Write;
 
-use crate::{context, percpu, sync::CleanLockToken, syscall::error::Result};
+use crate::{percpu, sync::CleanLockToken, syscall::error::Result};
 
 pub fn resource(token: &mut CleanLockToken) -> Result<Vec<u8>> {
     let mut string = String::new();

src/scheme/sys/stat.rs

@@ -1,7 +1,7 @@
 use core::fmt::Write as _;
 
 use crate::{
-    context::{ContextRef, Status},
+    context::Status,
     cpu_stats::{get_context_switch_count, get_contexts_count, irq_counts},
     percpu::{self, get_all_stats},
     sync::CleanLockToken,

src/scheme/sys/syscall.rs

@@ -2,7 +2,7 @@ use alloc::{string::String, vec::Vec};
 use core::fmt::Write;
 
 use crate::{
-    context, percpu,
+    percpu,
     sync::CleanLockToken,
     syscall::{self, error::Result},
 };