Merge branch 'af_unix-fix-two-data-races-reported-by-kcsan'

Kuniyuki Iwashima says:

====================
af_unix: Fix two data races reported by KCSAN.

KCSAN reported data races around these two fields for AF_UNIX sockets.

  * sk->sk_receive_queue->qlen
  * sk->sk_shutdown

Let's annotate them properly.
====================

Link: https://lore.kernel.org/r/20230510003456.42357-1-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>