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

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: 10993504d647 ("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>