Merge branch 'ipv4-v6-icmp-small-cleanup-and-update'

Kefeng Wang says:

====================
ipv4/v6: icmp: small cleanup and update

v2:
- Add cover letter and user proper patch subject-prefix suggested-by Eric Dumazet

This patch series contains some small cleanup and update,
1) use icmp/v6_sk_exit when icmp_sk_init fails instead of open-code
2) use new percpu allocation interface for the ipv6.icmp_sk
====================

Signed-off-by: David S. Miller <davem@davemloft.net>