Use pointer for wrappedConn methods (#17295)

Fix #17294

Signed-off-by: Andrew Thornton <art27@cantab.net>

modules/graceful/server.go

@@ -228,7 +228,7 @@ func (wl *wrappedListener) Accept() (net.Conn, error) {
 
 	closed := int32(0)
 
-	c = wrappedConn{
+	c = &wrappedConn{
 		Conn:                 c,
 		server:               wl.server,
 		closed:               &closed,
@@ -263,7 +263,7 @@ type wrappedConn struct {
 	perWritePerKbTimeout time.Duration
 }
 
-func (w wrappedConn) Write(p []byte) (n int, err error) {
+func (w *wrappedConn) Write(p []byte) (n int, err error) {
 	if w.perWriteTimeout > 0 {
 		minTimeout := time.Duration(len(p)/1024) * w.perWritePerKbTimeout
 		minDeadline := time.Now().Add(minTimeout).Add(w.perWriteTimeout)
@@ -277,7 +277,7 @@ func (w wrappedConn) Write(p []byte) (n int, err error) {
 	return w.Conn.Write(p)
 }
 
-func (w wrappedConn) Close() error {
+func (w *wrappedConn) Close() error {
 	if atomic.CompareAndSwapInt32(w.closed, 0, 1) {
 		defer func() {
 			if err := recover(); err != nil {