Some Kademlia code cleanup. (#1101)

protocols/kad/src/handler.rs

@@ -70,9 +70,6 @@ where
     /// We haven't started opening the outgoing substream yet.
     /// Contains the request we want to send, and the user data if we expect an answer.
     OutPendingOpen(KadRequestMsg, Option<TUserData>),
-    /// We are waiting for the outgoing substream to be upgraded.
-    /// Contains the request we want to send, and the user data if we expect an answer.
-    OutPendingUpgrade(KadRequestMsg, Option<TUserData>),
     /// Waiting to send a message to the remote.
     OutPendingSend(
         KadOutStreamSink<TSubstream>,
@@ -111,7 +108,6 @@ where
     fn try_close(self) -> AsyncSink<Self> {
         match self {
             SubstreamState::OutPendingOpen(_, _)
-            | SubstreamState::OutPendingUpgrade(_, _)
             | SubstreamState::OutReportError(_, _) => AsyncSink::Ready,
             SubstreamState::OutPendingSend(mut stream, _, _)
             | SubstreamState::OutPendingFlush(mut stream, _)
@@ -405,11 +401,8 @@ where
                 request_id,
             } => {
                 let pos = self.substreams.iter().position(|state| match state {
-                    SubstreamState::InWaitingUser(ref conn_id, _)
-                        if conn_id == &request_id.connec_unique_id =>
-                    {
-                        true
-                    }
+                    SubstreamState::InWaitingUser(ref conn_id, _) =>
+                        conn_id == &request_id.connec_unique_id,
                     _ => false,
                 });
 
@@ -562,11 +555,6 @@ where
             };
             (None, Some(ev), false)
         }
-        SubstreamState::OutPendingUpgrade(msg, user_data) => (
-            Some(SubstreamState::OutPendingUpgrade(msg, user_data)),
-            None,
-            false,
-        ),
         SubstreamState::OutPendingSend(mut substream, msg, user_data) => {
             match substream.start_send(msg) {
                 Ok(AsyncSink::Ready) => (