Cleanup / temp buffers for various things

peer/control/ping_test.go

@@ -59,7 +59,8 @@ func TestRoundTrip(t *testing.T) {
 
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
-			buf := tc.ping.Marshal()
+			var buf [control.Size]byte
+			tc.ping.Marshal(buf[:])
 			got, err := control.Unmarshal(buf)
 			if err != nil {
 				t.Fatalf("Unmarshal: %v", err)
@@ -80,7 +81,8 @@ func TestUnmarshalBadVersion(t *testing.T) {
 }
 
 func TestZeroEncoding(t *testing.T) {
-	buf := (control.Ping{}).Marshal()
+	var buf [control.Size]byte
+	(control.Ping{}).Marshal(buf[:])
 	for i, b := range buf {
 		if i == 0 {
 			continue // version byte