Addressed Trent's review

core/src/replay_stage.rs

@@ -2025,16 +2025,15 @@ impl ReplayStage {
             rooted_banks.push(root_bank.clone());
             let rooted_slots: Vec<_> = rooted_banks.iter().map(|bank| bank.slot()).collect();
             // The following differs from  rooted_slots by including the parent slot of the oldest parent bank.
-            let rooted_slots_with_parents = if bank_notification_sender
+            let rooted_slots_with_parents = bank_notification_sender
                 .as_ref()
                 .map_or(false, |sender| sender.should_send_parents)
-            {
-                let mut new_chain = rooted_slots.clone();
-                new_chain.push(oldest_parent.unwrap_or(bank.parent_slot()));
-                Some(new_chain)
-            } else {
-                None
-            };
+                .then(|| {
+                    let mut new_chain = rooted_slots.clone();
+                    new_chain.push(oldest_parent.unwrap_or(bank.parent_slot()));
+                    new_chain
+                });
+
             // Call leader schedule_cache.set_root() before blockstore.set_root() because
             // bank_forks.root is consumed by repair_service to update gossip, so we don't want to
             // get shreds for repair on gossip before we update leader schedule, otherwise they may