Remove Response::Error.

Error handling is already handled by Result; we don't need an "inner"
error variant duplicating the outer one.

zebra-network/src/peer/connection.rs

@@ -408,11 +408,6 @@ where
 
         match rsp {
             Response::Nil => { /* generic success, do nothing */ }
-            Response::Error => {
-                if let Err(e) = self.peer_tx.send(Message::from(PeerError::Rejected)).await {
-                    self.fail_with(e.into());
-                }
-            }
             Response::Peers(addrs) => {
                 if let Err(e) = self.peer_tx.send(Message::Addr(addrs)).await {
                     self.fail_with(e.into());

zebra-network/src/protocol/internal/response.rs

@@ -1,5 +1,3 @@
-use std::error::Error;
-
 // XXX clean module layout of zebra_chain
 use zebra_chain::block::Block;
 
@@ -11,21 +9,9 @@ pub enum Response {
     /// A response with no data.
     Nil,
 
-    /// Generic error.
-    Error,
-
     /// A list of peers, used to respond to `GetPeers`.
     Peers(Vec<MetaAddr>),
 
     /// A list of blocks.
     Blocks(Vec<Block>),
-}
-
-impl<E> From<E> for Response
-where
-    E: Error,
-{
-    fn from(_e: E) -> Self {
-        Self::Error
-    }
-}
+}