Bug#942734: bs1770gain does not escape file names properly in XML output

[Etienne Dechamps <etienne@edechamps.fr>]

Package: bs1770gain
Version: 0.6.5-1

Steps to reproduce:

$ sox -n '1 & 2.wav' synth 1 sine 1000
$ bs1770gain --xml --suppress-progress . | xmllint -
-:3: parser error : xmlParseEntityRef: no name
    <track total="1" number="1" file="1 & 2.wav">
                                         ^

Correct escaping would be "1 &amp; 2.wav".

This is a regression from bs1770gain 0.5.2-2, which did escape file names.