Add boards/ && cargo clippy

os/src/task/pid.rs

@@ -27,7 +27,7 @@ impl PidAllocator {
     pub fn dealloc(&mut self, pid: usize) {
         assert!(pid < self.current);
         assert!(
-            self.recycled.iter().find(|ppid| **ppid == pid).is_none(),
+            !self.recycled.iter().any(|ppid| *ppid == pid),
             "pid {} has been deallocated!",
             pid
         );