tiocmget: kill off the passing of the struct file

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 44b8412..97e3d50 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2648,7 +2648,7 @@
 	   to do here */
 }
 
-static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp)
+static int gsmtty_tiocmget(struct tty_struct *tty)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	return dlci->modem_rx;