Pull virtio fixes and cleanups from Michael Tsirkin:
 "This fixes the virtio-test tool, and improves the error handling for
  virtio-ccw"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: handle failures of READ_VQ_CONF ccw
  tools/virtio: propagate V=X to kernel build
  vhost: move features to core
  tools/virtio: fix build after 4.2 changes