Revert "vgacon: Add check for vc_origin address range in vgacon_scroll()"

This reverts commit 864f996.

The patch is wrong as it checks vc_origin against vc_screenbuf,
while in text mode it should compare against vga_vram_base.

As such it broke VGA text scrolling, which can be reproduced like this:
(1) boot a kernel that is configured to use text mode VGA-console
(2) type commands:  ls -l /usr/bin | less -S
(3) scroll up/down with cursor-down/up keys

Reported-by: Jari Ruusu <jariruusu@protonmail.com>
Cc: stable@vger.kernel.org
Cc: Yi Yang <yiyang13@huawei.com>
Cc: GONG Ruiqi <gongruiqi1@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Author: hdeller

drivers/video/console/vgacon.c

@@ -1168,7 +1168,7 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b,
 				     c->vc_screenbuf_size - delta);
 			c->vc_origin = vga_vram_end - c->vc_screenbuf_size;
 			vga_rolled_over = 0;
-		} else if (oldo - delta >= (unsigned long)c->vc_screenbuf)
+		} else
 			c->vc_origin -= delta;
 		c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size;
 		scr_memsetw((u16 *) (c->vc_origin), c->vc_video_erase_char,