ipv6: fix WARNING in ip6routenetexitlate()
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 v5.4.224 by commit 381453770f731f0f43616a1cd4c759b7807a1517, it was introduced in version v2.6.26 by commit cdb1876192dbe680b3ac955717fdf7f863c1762d. For more details please see the references link.