USB: core: message: fix sparse warning

Fix the following sparse warning:

drivers/usb/core/message.c:1583:6: warning: symbol '__usb_queue_reset_device' was not declared. Should it be static?
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/message.c

@@ -1633,7 +1633,7 @@ static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
  *
  * See usb_queue_reset_device() for more details
  */
-void __usb_queue_reset_device(struct work_struct *ws)
+static void __usb_queue_reset_device(struct work_struct *ws)
 {
 	int rc;
 	struct usb_interface *iface =