Merge tag 'pull-nbd-2021-11-16' of https://repo.or.cz/qemu/ericb into staging

nbd patches for 2021-11-16

- Rich Jones: Add 'qemu-nbd --selinux-label' option for running Unix
  socket with appropriate SELinux labeling
- Eric Blake: Address clang sanitizer warning

# gpg: Signature made Tue 16 Nov 2021 05:32:26 PM CET
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]

* tag 'pull-nbd-2021-11-16' of https://repo.or.cz/qemu/ericb:
  nbd/server: Add --selinux-label option
  nbd/server: Silence clang sanitizer warning

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