udlfb: set line_length in dlfb_ops_set_par

Set the variable "line_length" in the function dlfb_ops_set_par. Without
this, we get garbage if we select different videomode with fbset.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/udlfb.c

@@ -1057,6 +1057,7 @@ static int dlfb_ops_set_par(struct fb_info *info)
 		return result;
 
 	dlfb->current_mode = fvs;
+	info->fix.line_length = info->var.xres * (info->var.bits_per_pixel / 8);
 
 	if (dlfb->fb_count == 0) {