Refactor to async closures.

Signed-off-by: Jason Volk <jason@zemos.net>

src/service/rooms/event_handler/fetch_prev.rs

@@ -3,7 +3,7 @@ use std::{
 	iter::once,
 };
 
-use futures::{FutureExt, future};
+use futures::FutureExt;
 use ruma::{
 	CanonicalJsonValue, EventId, MilliSecondsSinceUnixEpoch, OwnedEventId, RoomId, ServerName,
 	int, uint,
@@ -110,7 +110,7 @@ where
 		}
 	}
 
-	let event_fetch = |event_id| {
+	let event_fetch = async |event_id: OwnedEventId| {
 		let origin_server_ts = eventid_info
 			.get(&event_id)
 			.map_or_else(|| uint!(0), |info| info.0.origin_server_ts().get());
@@ -118,7 +118,7 @@ where
 		// This return value is the key used for sorting events,
 		// events are then sorted by power level, time,
 		// and lexically by event_id.
-		future::ok((int!(0), MilliSecondsSinceUnixEpoch(origin_server_ts)))
+		Ok((int!(0), MilliSecondsSinceUnixEpoch(origin_server_ts)))
 	};
 
 	let sorted = state_res::lexicographical_topological_sort(&graph, &event_fetch)

src/service/rooms/event_handler/state_at_incoming.rs

@@ -128,7 +128,7 @@ where
 	new_state
 		.into_iter()
 		.stream()
-		.broad_then(|((event_type, state_key), event_id)| async move {
+		.broad_then(async |((event_type, state_key), event_id)| {
 			self.services
 				.short
 				.get_or_create_shortstatekey(&event_type, &state_key)

src/service/rooms/event_handler/upgrade_outlier_pdu.rs

@@ -167,7 +167,7 @@ where
 				.prev_events()
 				.any(is_equal_to!(event_id))
 		})
-		.broad_filter_map(|event_id| async move {
+		.broad_filter_map(async |event_id| {
 			// Only keep those extremities were not referenced yet
 			self.services
 				.pdu_metadata