Fixed more compile time errors

src/service/rooms/pdu_metadata/data.rs

@@ -1,6 +1,7 @@
 use std::sync::Arc;
 
 use ruma::{EventId, RoomId};
+use crate::Result;
 
 pub trait Data {
     fn mark_as_referenced(&self, room_id: &RoomId, event_ids: &[Arc<EventId>]) -> Result<()>;

src/service/rooms/pdu_metadata/mod.rs

@@ -4,13 +4,13 @@ use std::sync::Arc;
 pub use data::Data;
 use ruma::{RoomId, EventId};
 
-use crate::service::*;
+use crate::Result;
 
 pub struct Service<D: Data> {
     db: D,
 }
 
-impl Service<_> {
+impl<D: Data> Service<D> {
     #[tracing::instrument(skip(self, room_id, event_ids))]
     pub fn mark_as_referenced(&self, room_id: &RoomId, event_ids: &[Arc<EventId>]) -> Result<()> {
         self.db.mark_as_referenced(room_id, event_ids)