[PATCH] usb_unlink_urb: ratelimit warning

The warning about using unlink_urb needs to be rate limited, because
if a driver is still doing it will overrun the system logs.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/core/urb.c

@@ -451,9 +451,11 @@ int usb_unlink_urb(struct urb *urb)
 		return -EINVAL;
 	if (!(urb->transfer_flags & URB_ASYNC_UNLINK)) {
 #ifdef CONFIG_DEBUG_KERNEL
-		printk(KERN_NOTICE "usb_unlink_urb() is deprecated for "
-			"synchronous unlinks.  Use usb_kill_urb() instead.\n");
-		WARN_ON(1);
+		if (printk_ratelimit()) {
+			printk(KERN_NOTICE "usb_unlink_urb() is deprecated for "
+				"synchronous unlinks.  Use usb_kill_urb() instead.\n");
+			WARN_ON(1);
+		}
 #endif
 		usb_kill_urb(urb);
 		return 0;