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 v4.19.215 by commit 3dae1a4eced3ee733d7222e69b8a55caf2d61091, it was introduced in version v3.12 by commit 3f4ff561bc88b074d5e868dde4012d89cbb06c87. For more details please see the references link.