bug#56800: Pointless "Warning: desktop file appears to be in use by PID ###."

[Eli Zaretskii <eliz@gnu.org>]

> From: Paul Pogonyshev <pogonyshev@gmail.com>
> Date: Wed, 27 Jul 2022 19:52:31 +0200
> Cc: 56800@debbugs.gnu.org
> 
> Yeah, apparently `kill-emacs' is considered "low-level primitive":
> 
>     Functions to call with no arguments to query about killing Emacs.
>     If any of these functions returns nil, killing Emacs is canceled.
>     ‘save-buffers-kill-emacs’ calls these functions, but ‘kill-emacs’,
>     the low level primitive, does not.  See also ‘kill-emacs-hook’.
> 
> Since I have rebound C-x C-c for my private use (why waste such a nice shortcut on something used once
> in a few days?), I have been using `kill-emacs'. But apparently it's not what should be used... Emacs making
> it easy to silently break things, nothing new.
> 
> I suggest that `desktop-release-lock' call is still moved from something hooked on
> `kill-emacs-query-functions' to `kill-emacs-hook'. That part is supposed to be done unconditionally.

That change was made because the hook can ask questions, which doesn't
work in a daemon session.  So we moved the hook.