sm501fb: 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>
diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index 6294dca..a78254c 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -582,7 +582,7 @@
 {
 	struct sm501fb_par  *par = info->par;
 	struct sm501fb_info *fbi = par->info;
-	unsigned int bytes_pixel = var->bits_per_pixel / 8;
+	unsigned int bytes_pixel = info->var.bits_per_pixel / 8;
 	unsigned long reg;
 	unsigned long xoffs;
 
@@ -614,10 +614,10 @@
 	struct sm501fb_info *fbi = par->info;
 	unsigned long reg;
 
-	reg = var->xoffset | (var->xres_virtual << 16);
+	reg = var->xoffset | (info->var.xres_virtual << 16);
 	smc501_writel(reg, fbi->regs + SM501_DC_PANEL_FB_WIDTH);
 
-	reg = var->yoffset | (var->yres_virtual << 16);
+	reg = var->yoffset | (info->var.yres_virtual << 16);
 	smc501_writel(reg, fbi->regs + SM501_DC_PANEL_FB_HEIGHT);
 
 	sm501fb_sync_regs(fbi);