These traces contain some useless information (the always-0 source#) and
have no equivalents for XIVE mode.  For now just remove them, and we can
put back something more sensible if and when we need it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>