psi: using copy inside UpdateLocation() instead of range

stream/mts/psi/helpers.go

@@ -114,9 +114,7 @@ func UpdateLocation(d []byte, s string) error {
 		return errors.New("pmt does not location descriptor, cannot update")
 	}
 	gb := LocationStrBytes(s)
-	for i := range d[locationDataIndx : locationDataIndx+locationDataSize] {
-		d[i+locationDataIndx] = gb[i]
-	}
+	copy(d[locationDataIndx:locationDataIndx+locationDataSize], gb)
 	d = updateCrc(d)
 	return nil
 }