Fix saving abbrevs by 'abbrev-edit-save-buffer'

* lisp/abbrev.el (abbrev-edit-save-buffer): Reset
'abbrevs-changed'.  Suggested by Rick <rbielaws@gmail.com>.
(Bug#78435)

lisp/abbrev.el

@@ -289,7 +289,8 @@ abbrevs have been saved."
 The saved abbrevs are written to the file specified by
 `abbrev-file-name'."
   (interactive nil edit-abbrevs-mode)
-  (abbrev-edit-save-to-file abbrev-file-name))
+  (abbrev-edit-save-to-file abbrev-file-name)
+  (setq abbrevs-changed nil))
 
 
 (defun add-mode-abbrev (arg)