regmap: Fix possible double-free in regcacherbtreeexit()
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.4.157 by commit 1cead23c1c0bc766dacb900a3b0269f651ad596f, it was introduced in version v3.12 by commit 3f4ff561bc88b074d5e868dde4012d89cbb06c87. For more details please see the references link.