Revert "Fix buffer leak in mkcp transport protocol (#3347)"

This reverts commit d2b2f8c1f3d67134d78e79f1b82d7fd7a45cc0af.

transport/internet/kcp/connection.go

@@ -390,9 +390,7 @@ func (c *Connection) writeMultiBufferInternal(reader io.Reader) error {
 	}()
 
 	var b *buf.Buffer
-	defer func() {
-		b.Release()
-	}()
+	defer b.Release()
 
 	for {
 		for {
@@ -539,7 +537,6 @@ func (c *Connection) Terminate() {
 	c.closer.Close()
 	c.sendingWorker.Release()
 	c.receivingWorker.Release()
-	c.output.Release()
 }
 
 func (c *Connection) HandleOption(opt SegmentOption) {

transport/internet/kcp/output.go

@@ -10,7 +10,6 @@ import (
 
 type SegmentWriter interface {
 	Write(seg Segment) error
-	Release()
 }
 
 type SimpleSegmentWriter struct {
@@ -37,10 +36,6 @@ func (w *SimpleSegmentWriter) Write(seg Segment) error {
 	return err
 }
 
-func (w *SimpleSegmentWriter) Release() {
-	w.buffer.Release()
-}
-
 type RetryableWriter struct {
 	writer SegmentWriter
 }
@@ -56,7 +51,3 @@ func (w *RetryableWriter) Write(seg Segment) error {
 		return w.writer.Write(seg)
 	})
 }
-
-func (w *RetryableWriter) Release() {
-	w.writer.Release()
-}