s3c-fb: use display information in info not in var for panning

We must not use any information in the passed var besides xoffset,
yoffset and vmode as otherwise applications might abuse it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>

drivers/video/s3c-fb.c

@@ -883,7 +883,7 @@ static int s3c_fb_pan_display(struct fb_var_screeninfo *var,
 		}
 	}
 	/* Offset in bytes to the end of the displayed area */
-	end_boff = start_boff + var->yres * info->fix.line_length;
+	end_boff = start_boff + info->var.yres * info->fix.line_length;
 
 	/* Temporarily turn off per-vsync update from shadow registers until
 	 * both start and end addresses are updated to prevent corruption */