Apply clippy suggestions

So CI could be green on the other PR.

Author: stepancheg

src/map.rs

@@ -7679,7 +7679,7 @@ mod test_map {
         let vec: Vec<_> = (100..200).map(|i| (i, i)).collect();
         a.extend(iter);
         a.extend(&vec);
-        a.extend(&create_arr::<i32, 100>(200, 1));
+        a.extend(create_arr::<i32, 100>(200, 1));
 
         assert_eq!(a.len(), 300);
 

src/set.rs

@@ -2794,7 +2794,7 @@ mod test_set {
         let mut a = HashSet::new();
         a.insert(1);
 
-        a.extend(&[2, 3, 4]);
+        a.extend([2, 3, 4]);
 
         assert_eq!(a.len(), 4);
         assert!(a.contains(&1));