ipv6: mcast: use rcu-safe version of ipv6getlladdr()
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 v5.15.25 by commit 3e11ef1903cf6c2fba35594b193a3570854d9e9e, it was introduced in version v5.13 by commit 88e2ca3080947fe22eb520c1f8231e79a105d011. For more details please see the references link.