ipack: ipoctal: fix stack information leak

In the Linux kernel, the following vulnerability has been resolved: ipack: ipoctal: fix stack information leak The tty driver name is used also after registering the driver and must specifically not be allocated on the stack to avoid leaking information to user space (or triggering an oops). Drivers should not try to encode topology information in the tty device name but this one snuck in through staging without anyone noticing and another driver has since copied this malpractice. Fixing the ABI is a separate issue, but this at least plugs the security hole.