Since we have normal ticketed flushing and preemptive flushing, adjust the tracepoint so that we know the source of the flushing action to make it easier to debug problems. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>