fixed some linting errors

found them using

```
gometalinter --skip=vendor --disable-all --enable=megacheck --enable=deadcode --enable=ineffassign --enable=interfacer --enable=errcheck ./...
```

dht/contact.go

@@ -108,12 +108,7 @@ func (c *Contact) UnmarshalBencode(b []byte) error {
 		return errors.Err("invalid IP")
 	}
 
-	err = bencode.DecodeBytes(raw[2], &c.Port)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return bencode.DecodeBytes(raw[2], &c.Port)
 }
 
 func sortByDistance(contacts []Contact, target bits.Bitmap) {

dht/dht.go

@@ -70,11 +70,7 @@ func (dht *DHT) connect(conn UDPConn) error {
 	dht.node = NewNode(contact.ID)
 	dht.tokenCache = newTokenCache(dht.node, tokenSecretRotationInterval)
 
-	err = dht.node.Connect(conn)
-	if err != nil {
-		return err
-	}
-	return nil
+	return dht.node.Connect(conn)
 }
 
 // Start starts the dht

dht/dht_announce.go

@@ -57,7 +57,11 @@ func (dht *DHT) runAnnouncer() {
 		defer dht.grp.Done()
 		limiter := rate.NewLimiter(rate.Limit(dht.conf.AnnounceRate), dht.conf.AnnounceRate)
 		for {
-			limiter.Wait(context.Background()) // TODO: should use grp.ctx somehow? so when grp is closed, wait returns
+			err := limiter.Wait(context.Background()) // TODO: should use grp.ctx somehow? so when grp is closed, wait returns
+			if err != nil {
+				log.Error(errors.Prefix("rate limiter", err))
+				continue
+			}
 			select {
 			case limitCh <- time.Now():
 			case <-dht.grp.Ch():

dht/node_finder.go

@@ -250,10 +250,6 @@ func (cf *contactFinder) probe(cycleID string) *Contact {
 	return cf.closest(res.Contacts...)
 }
 
-func (cf *contactFinder) probeClosestOutstanding() {
-
-}
-
 // appendNewToShortlist appends any new contacts to the shortlist and sorts it by distance
 // contacts that have already been added to the shortlist in the past are ignored
 func (cf *contactFinder) appendNewToShortlist(contacts []Contact) {
@@ -320,11 +316,7 @@ func (cf *contactFinder) isSearchFinished() bool {
 
 	cf.activeContactsMutex.Lock()
 	defer cf.activeContactsMutex.Unlock()
-	if len(cf.activeContacts) >= bucketSize {
-		return true
-	}
-
-	return false
+	return len(cf.activeContacts) >= bucketSize
 }
 
 func (cf *contactFinder) debug(format string, args ...interface{}) {

dht/routing_table.go

@@ -263,14 +263,20 @@ func (rt *routingTable) Update(c Contact) {
 		}
 	}
 
-	b.UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, true)
+	err := b.UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, true)
+	if err != nil {
+		log.Error(err)
+	}
 }
 
 // Fresh refreshes a contact if its already in the routing table
 func (rt *routingTable) Fresh(c Contact) {
 	rt.mu.RLock()
 	defer rt.mu.RUnlock()
-	rt.bucketFor(c.ID).UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, false)
+	err := rt.bucketFor(c.ID).UpdatePeer(peer{Contact: c, Distance: rt.id.Xor(c.ID)}, false)
+	if err != nil {
+		log.Error(err)
+	}
 }
 
 // FailContact marks a contact as having failed, and removes it if it failed too many times

dht/rpc.go

@@ -110,6 +110,9 @@ func (rpc *rpcReceiver) IterativeFindValue(r *http.Request, args *RpcIterativeFi
 		return err
 	}
 	foundContacts, found, err := FindContacts(rpc.dht.node, key, false, nil)
+	if err != nil {
+		return err
+	}
 	result.Contacts = foundContacts
 	result.FoundValue = found
 	return nil
@@ -153,7 +156,11 @@ func (dht *DHT) runRPCServer(port int) {
 	s := rpc2.NewServer()
 	s.RegisterCodec(json.NewCodec(), "application/json")
 	s.RegisterCodec(json.NewCodec(), "application/json;charset=UTF-8")
-	s.RegisterService(&rpcReceiver{dht: dht}, "rpc")
+	err := s.RegisterService(&rpcReceiver{dht: dht}, "rpc")
+	if err != nil {
+		log.Error(errors.Prefix("registering rpc service", err))
+		return
+	}
 
 	handler := mux.NewRouter()
 	handler.Handle("/", s)
@@ -171,6 +178,10 @@ func (dht *DHT) runRPCServer(port int) {
 	}()
 
 	<-dht.grp.Ch()
-	server.Shutdown(context.Background())
+	err = server.Shutdown(context.Background())
+	if err != nil {
+		log.Error(errors.Prefix("shutting down rpc service", err))
+		return
+	}
 	wg.Wait()
 }