tty: n_gsm: Add compat_ioctl

To use this driver with 32 bit userspace applications on 64 bit
kernels a compat_ioctl is needed.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_gsm.c

@@ -2607,6 +2607,14 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
 	}
 }
 
+#ifdef CONFIG_COMPAT
+static long gsmld_compat_ioctl(struct tty_struct *tty, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	return gsmld_ioctl(tty, file, cmd, arg);
+}
+#endif
+
 /*
  *	Network interface
  *
@@ -2818,6 +2826,9 @@ static struct tty_ldisc_ops tty_ldisc_packet = {
 	.flush_buffer    = gsmld_flush_buffer,
 	.read            = gsmld_read,
 	.write           = gsmld_write,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl    = gsmld_compat_ioctl,
+#endif
 	.ioctl           = gsmld_ioctl,
 	.poll            = gsmld_poll,
 	.receive_buf     = gsmld_receive_buf,