test: fix all clippy lints in tests (#2573)

ci/azure-clippy.yml

@@ -12,5 +12,5 @@ jobs:
         cargo clippy --version
       displayName: Install clippy
     - script: |
-        cargo clippy --all --all-features
-      displayName: cargo clippy --all
+        cargo clippy --all --all-features --tests
+      displayName: cargo clippy --all --tests

tokio/src/sync/tests/semaphore_batch.rs

@@ -236,7 +236,7 @@ fn close_semaphore_notifies_permit2() {
 #[test]
 fn cancel_acquire_releases_permits() {
     let s = Semaphore::new(10);
-    let _permit1 = s.try_acquire(4).expect("uncontended try_acquire succeeds");
+    s.try_acquire(4).expect("uncontended try_acquire succeeds");
     assert_eq!(6, s.available_permits());
 
     let mut acquire = task::spawn(s.acquire(8));

tokio/tests/macros_join.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::blacklisted_name)]
 use tokio::sync::oneshot;
 use tokio_test::{assert_pending, assert_ready, task};
 

tokio/tests/macros_select.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::blacklisted_name)]
 use tokio::sync::{mpsc, oneshot};
 use tokio::task;
 use tokio_test::{assert_ok, assert_pending, assert_ready};

tokio/tests/macros_try_join.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::blacklisted_name)]
 use tokio::sync::oneshot;
 use tokio_test::{assert_pending, assert_ready, task};
 

tokio/tests/sync_mutex_owned.rs

@@ -36,7 +36,7 @@ fn straight_execution() {
 fn readiness() {
     let l = Arc::new(Mutex::new(100));
     let mut t1 = spawn(l.clone().lock_owned());
-    let mut t2 = spawn(l.clone().lock_owned());
+    let mut t2 = spawn(l.lock_owned());
 
     let g = assert_ready!(t1.poll());
 

tokio/tests/time_delay_queue.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::blacklisted_name)]
 #![warn(rust_2018_idioms)]
 #![cfg(feature = "full")]