packer/rpc: clean up unnecessary functions

packer/rpc/muxconn.go

@@ -418,14 +418,6 @@ func (s *Stream) remoteClose() {
 	s.writeCh <- nil
 }
 
-func (s *Stream) registerStateListener(ch chan<- streamState) {
-	s.stateChange[ch] = struct{}{}
-}
-
-func (s *Stream) deregisterStateListener(ch chan<- streamState) {
-	delete(s.stateChange, ch)
-}
-
 func (s *Stream) setState(state streamState) {
 	log.Printf("[TRACE] Stream %d went to state %d", s.id, state)
 	s.state = state
@@ -441,12 +433,12 @@ func (s *Stream) setState(state streamState) {
 func (s *Stream) waitState(target streamState) error {
 	// Register a state change listener to wait for changes
 	stateCh := make(chan streamState, 10)
-	s.registerStateListener(stateCh)
+	s.stateChange[stateCh] = struct{}{}
 	s.mu.Unlock()
 
 	defer func() {
 		s.mu.Lock()
-		s.deregisterStateListener(stateCh)
+		delete(s.stateChange, stateCh)
 	}()
 
 	state := <-stateCh