fbcon: Don't reset logo_shown when logo is currently shown

When the logo is currently drawn on a virtual console, and the console
loglevel is reduced to quiet, logo_shown must be left alone, so that it
the scrolling region on that virtual console is properly reset.

Fixes: 10993504 ("fbcon: Silence fbcon logo on 'quiet' boots")
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Marko Myllynen <myllynen@redhat.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/core/fbcon.c

@@ -1069,7 +1069,7 @@ static void fbcon_init(struct vc_data *vc, int init)
 
 	cap = info->flags;
 
-	if (console_loglevel <= CONSOLE_LOGLEVEL_QUIET)
+	if (logo_shown < 0 && console_loglevel <= CONSOLE_LOGLEVEL_QUIET)
 		logo_shown = FBCON_LOGO_DONTSHOW;
 
 	if (vc != svc || logo_shown == FBCON_LOGO_DONTSHOW ||