mm/mempolicy: fix uninit-value in mpolrebindpolicy()
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 v5.18.15 by commit 777e563f10e91e91130fe06bee85220d508e7b9b. For more details please see the references link.