psi: trimming excess bytes in gps data from pmt

stream/mts/psi/op.go

@@ -28,6 +28,7 @@ LICENSE
 package psi
 
 import (
+	"bytes"
 	"encoding/binary"
 	"errors"
 	"hash/crc32"
@@ -101,6 +102,7 @@ func GpsOf(p []byte) (g string, err error) {
 		return "", err
 	}
 	gBytes := p[gpsDataIndx : gpsDataIndx+gpsDataSize]
+	gBytes = bytes.Trim(gBytes, "\x00")
 	g = string(gBytes)
 	return g, nil
 }