fbcon: Consistently protect deferred_takeover with console_lock()

This shouldn't be a problem in practice since until we've actually
taken over the console there's nothing we've registered with the
console/vt subsystem, so the exit/unbind path that check this can't
do the wrong thing. But it's confusing, so fix it by moving it a tad
later.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-14-daniel.vetter@ffwll.ch

drivers/video/fbdev/core/fbcon.c

@@ -3227,6 +3227,9 @@ static void fbcon_register_existing_fbs(struct work_struct *work)
 
 	console_lock();
 
+	deferred_takeover = false;
+	logo_shown = FBCON_LOGO_DONTSHOW;
+
 	for_each_registered_fb(i)
 		fbcon_fb_registered(registered_fb[i]);
 
@@ -3244,8 +3247,6 @@ static int fbcon_output_notifier(struct notifier_block *nb,
 	pr_info("fbcon: Taking over console\n");
 
 	dummycon_unregister_output_notifier(&fbcon_output_nb);
-	deferred_takeover = false;
-	logo_shown = FBCON_LOGO_DONTSHOW;
 
 	/* We may get called in atomic context */
 	schedule_work(&fbcon_deferred_takeover_work);