wifi: iwlwifi: fix double-free bug

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: fix double-free bug The storage for the TLV PC register data wasn't done like all the other storage in the drv->fw area, which is cleared at the end of deallocation. Therefore, the freeing must also be done differently, explicitly NULL'ing it out after the free, since otherwise there's a nasty double-free bug here if a file fails to load after this has been parsed, and we get another free later (e.g. because no other file exists.) Fix that by adding the missing NULL assignment.

References

• https://git.kernel.org/stable/c/ab9d4bb9a1892439b3123fc52b19e32b9cdf80ad
• https://git.kernel.org/stable/c/d24eb9a27bea8fe5237fa71be274391d9d51eff2
• https://git.kernel.org/stable/c/353d321f63f7dbfc9ef58498cc732c9fe886a596