Fix mmap_is_attached_or_noreserve

[Ken Brown]

Hi Takashi,

On 12/27/2024 7:06 AM, Takashi Yano wrote:
> On Thu, 26 Dec 2024 11:56:00 -0500
> Ken Brown wrote:
>> +  LIST_WRITE_LOCK ();
> 
> This patch atempt to acquire lock despite the lock has been
> already acquired. I think this is the cause of deadlock.
Thank you!!  I can't tell you how many times I went over the patch and 
didn't see that.

In the meantime, I've found a simpler solution to the problem.  I'll 
send a v2 patch later.

Ken