remove re-export of parking_lot in util (#6435)

ethcore/light/src/net/mod.rs

@@ -24,7 +24,8 @@ use io::TimerToken;
 use network::{HostInfo, NetworkProtocolHandler, NetworkContext, PeerId};
 use rlp::{RlpStream, UntrustedRlp};
 use util::hash::H256;
-use util::{DBValue, Mutex, RwLock, U256};
+use util::{DBValue, U256};
+use parking_lot::{Mutex, RwLock};
 use time::{Duration, SteadyTime};
 
 use std::collections::{HashMap, HashSet};
@@ -287,7 +288,7 @@ pub type PeerMap = HashMap<PeerId, Mutex<Peer>>;
 mod id_guard {
 
 	use network::PeerId;
-	use util::RwLockReadGuard;
+	use parking_lot::RwLockReadGuard;
 
 	use super::{PeerMap, ReqId};