kernel: IPv6: panic in fib6_rule_suppress when fib6_rule_lookup fails

A flaw was found in the IPv6 module of the Linux kernel. The arg.result was not used consistently in fib6rulelookup, sometimes holding rt6info and other times fib6info. This was not accounted for in other parts of the code where rt6info was expected unconditionally, potentially leading to a kerne...