benches: fix build

Signed-off-by: Marc-Antoine Perennou <[email protected]>

Author: Keruspe

Diff for: benches/task_local.rs

@@ -13,8 +13,10 @@ fn get(b: &mut Bencher) {
     }
 
     let mut sum = 0;
-    task::block_on(async {
-        b.iter(|| VAL.with(|v| sum += v));
+    b.iter(|| {
+        task::block_on(async move {
+            VAL.with(|v| sum += v);
+        })
     });
     black_box(sum);
 }