fs: fix UAF/GPF bug in nilfsmdtdestroy
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 v4.9.331 by commit d1ff475d7c83289d0a7faef346ea3bbf90818bad. For more details please see the references link.