[PATCH] USB: fix usb-serial generic initialization

At module load time, if a generic device is found, the tty information
for the device is not set up properly (as the tty structures aren't initialized
yet.)  This can cause big problems for things like udev.  This patch fixes this.

Thanks to Kay Sievers for the original patch for this problem.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>