tty: USB does not need the filp argument in the drivers

And indeed none of them use it. Clean this up as it will make moving to a
standard open method rather easier.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/usb_debug.c b/drivers/usb/serial/usb_debug.c
index 6148009..7b5bfc4 100644
--- a/drivers/usb/serial/usb_debug.c
+++ b/drivers/usb/serial/usb_debug.c
@@ -43,11 +43,10 @@
 	.no_dynamic_id = 	1,
 };
 
-static int usb_debug_open(struct tty_struct *tty, struct usb_serial_port *port,
-							struct file *filp)
+static int usb_debug_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	port->bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE;
-	return usb_serial_generic_open(tty, port, filp);
+	return usb_serial_generic_open(tty, port);
 }
 
 /* This HW really does not support a serial break, so one will be