Merge branch 'ping6-cmsg'

Jakub Kicinski says:

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net: ping6: support basic socket cmsgs

Add support for common SOL_SOCKET cmsgs in ICMPv6 sockets.
Extend the cmsg tests to cover more cmsgs and socket types.

SOL_IPV6 cmsgs to follow.
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Signed-off-by: David S. Miller <davem@davemloft.net>