btrfs: do not BUGON in linktofixupdir
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 v4.4.271 by commit 76bfd8ac20bebeae599452a03dfc5724c0475dcf, it was introduced in version by commit . For more details please see the references link.