Bluetooth: Remove stub ioctl in hci_vhci

Remove the empty ioctl which just returns -EINVAL. vfs_ioctl() will
return -ENOTTY instead, but I doubt that any application will notice
the difference :)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>