TEST: Upgrade pion to v3.2.9. (#3567)

------

Co-authored-by: chundonglinlin <chundonglinlin@163.com>

trunk/3rdparty/srs-bench/vendor/github.com/pion/rtcp/goodbye.go

@@ -2,6 +2,7 @@ package rtcp
 
 import (
 	"encoding/binary"
+	"fmt"
 )
 
 // The Goodbye packet indicates that one or more sources are no longer active.
@@ -12,8 +13,6 @@ type Goodbye struct {
 	Reason string
 }
 
-var _ Packet = (*Goodbye)(nil) // assert is a Packet
-
 // Marshal encodes the Goodbye packet in binary
 func (g Goodbye) Marshal() ([]byte, error) {
 	/*
@@ -144,3 +143,13 @@ func (g *Goodbye) DestinationSSRC() []uint32 {
 	copy(out, g.Sources)
 	return out
 }
+
+func (g Goodbye) String() string {
+	out := "Goodbye\n"
+	for i, s := range g.Sources {
+		out += fmt.Sprintf("\tSource %d: %x\n", i, s)
+	}
+	out += fmt.Sprintf("\tReason: %s\n", g.Reason)
+
+	return out
+}