CVE-2025-71184 btrfs: fix NULL dereference on root when tracing inode eviction

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix NULL dereference on root when tracing inode eviction When evicting an inode the first thing we do is to setup tracing for it, which implies fetching the root's id. But in btrfsevictinode the root might be NULL, as...