aufs: adjust for v6.9+

The following commit drops SLAB_MEM_SPREAD, so we remove it
from aufs.

commit cdeeaaba
Author: Vlastimil Babka <vbabka@suse.cz>
Date:   Fri Feb 23 19:27:17 2024 +0100

    mm, slab: deprecate SLAB_MEM_SPREAD flag

    The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
    removed.  SLUB instead relies on the page allocator's NUMA policies.
    Change the flag's value to 0 to free up the value it had, and mark it
    for full removal once all users are gone.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
    Closes: https://lore.kernel.org/all/20240131172027.10f64405@gandalf.local.home/


Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>