Merge branch 'hdrs-for-dump-req' into iproute2-next

David Ahern says:

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iproute2 currently uses ifinfomsg as the header for all dumps using the
wilddump headers. This is wrong as each message type actually has its own
header type. While the kernel has traditionally let it go as it for the
most part only uses the family entry, the use of kernel side filters is
increasing to alter what is returned on a request. The kernel side filters
really need to use the proper header type.

To that end, fix iproute2 to use the proper header struct for the GET type.

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Signed-off-by: David Ahern <dsahern@gmail.com>