Merge remote-tracking branch 'remotes/dagrh/tags/pull-virtiofs-20211026' into staging

Virtiofsd pull 2021-10-26

New 'unsupported' feature for xattr mapping
  Good for hiding selinux

Plus some tidy ups and error handling.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Tue 26 Oct 2021 03:28:44 AM PDT
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]

* remotes/dagrh/tags/pull-virtiofs-20211026:
  virtiofsd: Error on bad socket group name
  virtiofsd: Add a helper to stop all queues
  virtiofsd: Add a helper to send element on virtqueue
  virtiofsd: Remove unused virtio_fs_config definition
  virtiofsd: xattr mapping add a new type "unsupported"

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>