Simplify modeline buffer roam relabelling

Hopefully more robust too

config.org

@@ -4210,7 +4210,7 @@ Hence, we need to do a bit of overriding.
 All those numbers! It's messy. Let's adjust this in a similar way that I have in
 the[[*Window title][Window title]].
 #+begin_src emacs-lisp
-(defadvice! doom-modeline--reformat-roam (orig-fun)
+(defadvice! doom-modeline--buffer-file-name-roam-aware-a ()
   :around #'doom-modeline-buffer-file-name
   (message "Reformat?")
   (message (buffer-file-name))
@@ -4218,7 +4218,7 @@ the[[*Window title][Window title]].
       (replace-regexp-in-string
        "\\(?:^\\|.*/\\)\\([0-9]\\{4\\}\\)\\([0-9]\\{2\\}\\)\\([0-9]\\{2\\}\\)[0-9]*-"
        "🢔(\\1-\\2-\\3) "
-       (funcall orig-fun))
+       (subst-char-in-string ?_ ?  buffer-file-name))
     (funcall orig-fun)))
 #+end_src
 **** Nicer generated heading IDs