fbcon: call fbcon_fb_bind directly

Also remove the error return value. That's all errors for either
driver bugs (trying to unbind something that isn't bound), or errors
of the new driver that will take over.

There's nothing the outgoing driver can do about this anyway, so
switch over to void.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-18-daniel.vetter@ffwll.ch

include/linux/fb.h

@@ -158,8 +158,6 @@ struct fb_cursor_user {
 #define FB_EVENT_CONBLANK               0x0C
 /*      Get drawing requirements        */
 #define FB_EVENT_GET_REQ                0x0D
-/*      Unbind from the console if possible */
-#define FB_EVENT_FB_UNBIND              0x0E
 /*      CONSOLE-SPECIFIC: remap all consoles to new fb - for vga_switcheroo */
 #define FB_EVENT_REMAP_ALL_CONSOLE      0x0F
 /*      A hardware display blank early change occurred */