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/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 8fec5d4..76a17f9 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -747,8 +747,7 @@
 					const struct usb_device_id *id);
 static int  ftdi_sio_port_probe(struct usb_serial_port *port);
 static int  ftdi_sio_port_remove(struct usb_serial_port *port);
-static int  ftdi_open(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp);
+static int  ftdi_open(struct tty_struct *tty, struct usb_serial_port *port);
 static void ftdi_close(struct usb_serial_port *port);
 static void ftdi_dtr_rts(struct usb_serial_port *port, int on);
 static int  ftdi_write(struct tty_struct *tty, struct usb_serial_port *port,
@@ -1680,8 +1679,7 @@
 	return 0;
 }
 
-static int ftdi_open(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp)
+static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
 { /* ftdi_open */
 	struct usb_device *dev = port->serial->dev;
 	struct ftdi_private *priv = usb_get_serial_port_data(port);