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/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 8d126dd..81f2ae5 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -146,7 +146,7 @@
 static int  whiteheat_attach(struct usb_serial *serial);
 static void whiteheat_release(struct usb_serial *serial);
 static int  whiteheat_open(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp);
+			struct usb_serial_port *port);
 static void whiteheat_close(struct usb_serial_port *port);
 static int  whiteheat_write(struct tty_struct *tty,
 			struct usb_serial_port *port,
@@ -659,8 +659,7 @@
 	return;
 }
 
-static int whiteheat_open(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp)
+static int whiteheat_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	int		retval = 0;