Pull vfs fix from Christian Brauner:
 "During the pipe nonblock rework the check for both O_NONBLOCK and
  IOCB_NOWAIT was dropped. Both checks need to be performed to ensure
  that files without O_NONBLOCK but IOCB_NOWAIT don't block when writing
  to or reading from a pipe.

  This just contains the fix adding the check for IOCB_NOWAIT back in"

* tag 'vfs/v6.4-rc1/pipe' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
  pipe: check for IOCB_NOWAIT alongside O_NONBLOCK