f2fs: fix to avoid touching checkpointed data in get_victim()
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 v5.12.5 by commit 211372b2571520e394b56b431a0705586013b3ff, it was introduced in version v4.20 by commit 4354994f097d068a894aa1a0860da54571df3582. For more details please see the references link.