fix(iota-core): code cleanup

crates/iota-core/src/authority.rs

@@ -4647,12 +4647,11 @@ impl AuthorityState {
             .events
             .data
             .iter()
-            .find(|event| event.is_system_epoch_info_event());
-        let system_epoch_info_event = system_epoch_info_event.map(|event| {
-            bcs::from_bytes::<SystemEpochInfoEventV1>(&event.contents).expect(
-                "deserialization should succeed since we asserted that the event is of this type",
-            )
-        });
+            .find(|event| event.is_system_epoch_info_event())
+            .map(|event| {
+                bcs::from_bytes::<SystemEpochInfoEventV1>(&event.contents)
+                    .expect("event deserialization should succeed as type was pre-validated")
+            });
         // The system epoch info event can be `None` in case if the `advance_epoch`
         // Move function call failed and was executed in the safe mode.
         assert!(system_epoch_info_event.is_some() || system_obj.safe_mode());