fs: jfs: fix shift-out-of-bounds in dbDiscardAG
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 v4.9.337 by commit f8d4d0bac603616e2fa4a3907e81ed13f8f3c380. For more details please see the references link.