obtains staked-nodes from the root-bank (#14257)

... as opposed to the working bank

core/src/optimistically_confirmed_bank_tracker.rs

@@ -23,7 +23,7 @@ pub struct OptimisticallyConfirmedBank {
 impl OptimisticallyConfirmedBank {
     pub fn locked_from_bank_forks_root(bank_forks: &Arc<RwLock<BankForks>>) -> Arc<RwLock<Self>> {
         Arc::new(RwLock::new(Self {
-            bank: bank_forks.read().unwrap().root_bank().clone(),
+            bank: bank_forks.read().unwrap().root_bank(),
         }))
     }
 }