style: Fix clippy lint errors

src/service/migrations.rs

@@ -573,7 +573,7 @@ async fn fix_readreceiptid_readreceipt_duplicates(services: &Services) -> Result
 	db.db.sort()
 }
 
-const FIXED_CORRUPT_MSC4133_FIELDS_MARKER: &'static [u8] = b"fix_corrupt_msc4133_fields";
+const FIXED_CORRUPT_MSC4133_FIELDS_MARKER: &[u8] = b"fix_corrupt_msc4133_fields";
 async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
 	use serde_json::{Value, from_slice};
 	type KeyVal<'a> = ((OwnedUserId, String), &'a [u8]);
@@ -588,7 +588,7 @@ async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
 		.stream()
 		.try_fold(
 			(0_usize, 0_usize),
-			async |(mut total, mut fixed),
+			async |(total, mut fixed),
 			       ((user, key), value): KeyVal<'_>|
 			       -> Result<(usize, usize)> {
 				if let Err(error) = from_slice::<Value>(value) {
@@ -607,9 +607,8 @@ async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
 					};
 
 					useridprofilekey_value.put((user, key), new_value);
-					fixed += 1;
 				}
-				total += 1;
+				fixed = total.saturating_add(1);
 
 				Ok((total, fixed))
 			},

src/service/users/mod.rs

@@ -1113,7 +1113,7 @@ impl Service {
 			.useridprofilekey_value
 			.qry(&key)
 			.await
-			.and_then(|handle| serde_json::from_slice(&handle).map_err(|err| err.into()))
+			.and_then(|handle| serde_json::from_slice(&handle).map_err(Into::into))
 	}
 
 	/// Gets all the user's profile keys and values in an iterator