Either the callback is mandatory to implement, in which case an assert()
is more appropriate, or it's not and we can't tell much whether the
function should fail or not (given it's name, I guess it should silently
success by default). Instead, make the implementation mandatory and
vhost-user specific to be more clear about its usage.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>