thermal: of: fix double-free on unregistration

In the Linux kernel, the following vulnerability has been resolved: thermal: of: fix double-free on unregistration Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure"), thermal_zone_device_register() allocates a copy of the tzp argument and frees it when unregistering, so thermal_of_zone_register() now ends up leaking its original tzp and double-freeing the tzp copy. Fix this by locating tzp on stack instead.