This is necessary so that we get properly woken up to write the rest.
This patch also changes the len argument to the have_data callback, to
avoid doing an unsigned signed comparison.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>