run rustfmt on libstd/collections/hash folder

Author: srinivasreddy

src/libstd/collections/hash/bench.rs

@@ -15,17 +15,17 @@ extern crate test;
 use self::test::Bencher;
 
 #[bench]
-fn new_drop(b : &mut Bencher) {
+fn new_drop(b: &mut Bencher) {
     use super::map::HashMap;
 
     b.iter(|| {
-        let m : HashMap<i32, i32> = HashMap::new();
+        let m: HashMap<i32, i32> = HashMap::new();
         assert_eq!(m.len(), 0);
     })
 }
 
 #[bench]
-fn new_insert_drop(b : &mut Bencher) {
+fn new_insert_drop(b: &mut Bencher) {
     use super::map::HashMap;
 
     b.iter(|| {