icmp6 error statistics based on sending interface.
This also prevent kernel panic when rcvif is not initialized after M_PKTHDR().
(The initialization issue also need to be fixed in the future.)
Approved by: jkh
Submitted by: k-sugyou@kame.net
Yes it is almost code freeze, but as the result of many thought, now I
think this should be added before 4.0...
make world check, kernel build check is done.
Reviewed by: green
Obtained from: KAME project
