MAINTAINERS: update virtio-fs mailing list address

MAINTAINERS: update virtio-fs mailing list address

The old virtio-fs mailing list address is no longer in use. Switch to
the new mailing list address.

Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: German Maglione <gmaglione@redhat.com>
Cc: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: German Maglione <gmaglione@redhat.com>
Message-ID: <20231111004920.148348-1-stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>