Variable int err in inner scope shadows Error *err in outer scope.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191205174635.18758-3-vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>