Pull virtio docs and tests from Michael Tsirkin:
 "This merely has some documentation and a new test, seems safe to
  merge"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  tools/virtio: add noring tool
  tools/virtio/ringtest: fix run-on-all.sh to work without /dev/cpu
  tools/virtio/ringtest: add usage example to README
  MAINTAINERS: Add file patterns for virtio device tree bindings