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/keyspan.h b/drivers/usb/serial/keyspan.h
index 3107ed1..30771e5 100644
--- a/drivers/usb/serial/keyspan.h
+++ b/drivers/usb/serial/keyspan.h
@@ -36,8 +36,7 @@
 
 /* Function prototypes for Keyspan serial converter */
 static int  keyspan_open		(struct tty_struct *tty,
-					 struct usb_serial_port *port,
-					 struct file *filp);
+					 struct usb_serial_port *port);
 static void keyspan_close		(struct usb_serial_port *port);
 static void keyspan_dtr_rts		(struct usb_serial_port *port, int on);
 static int  keyspan_startup		(struct usb_serial *serial);