chore: add missing symbol and remote the unnecessary symbol in comment

Signed-off-by: xixishidibei <[email protected]>

cstrml/balances/src/tests.rs

@@ -268,7 +268,7 @@ macro_rules! decl_tests {
 					assert_eq!(Balances::total_balance(&2), 256 * 20);
 
 					assert_ok!(Balances::reserve(&2, 256 * 19 + 1)); // account 2 becomes mostly reserved
-					assert_eq!(Balances::free_balance(2), 255); // "free" account deleted."
+					assert_eq!(Balances::free_balance(2), 255); // "free" account deleted.
 					assert_eq!(Balances::total_balance(&2), 256 * 20); // reserve still exists.
 					assert_eq!(System::account_nonce(&2), 1);
 

utils/ring/src/pbkdf2.rs

@@ -111,6 +111,7 @@
 //!     // An attempt to log in with the right password succeeds.
 //!     assert!(db.verify_password("alice", "@74d7]404j|W}6u").is_ok());
 //! }
+//! ```
 
 use crate::{constant_time, digest, error, hmac, polyfill};
 use core::num::NonZeroU32;