WorkStruct: make allyesconfig

Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 8006e51..2cfba84 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -533,9 +533,10 @@
 	schedule_work(&port->work);
 }
 
-static void usb_serial_port_work(void *private)
+static void usb_serial_port_work(struct work_struct *work)
 {
-	struct usb_serial_port *port = private;
+	struct usb_serial_port *port =
+		container_of(work, struct usb_serial_port, work);
 	struct tty_struct *tty;
 
 	dbg("%s - port %d", __FUNCTION__, port->number);
@@ -799,7 +800,7 @@
 		port->serial = serial;
 		spin_lock_init(&port->lock);
 		mutex_init(&port->mutex);
-		INIT_WORK(&port->work, usb_serial_port_work, port);
+		INIT_WORK(&port->work, usb_serial_port_work);
 		serial->port[i] = port;
 	}