Rename rtnl_wilddump_req_filter to rtnl_linkdump_req_filter,
rtnl_wilddump_request to rtnl_linkdump_req and
rtnl_wilddump_req_filter_fn to rtnl_linkdump_req_filter_fn.
In all cases drop the type argument which at this point is only
RTM_GETLINK and hardcode in the functions.
Signed-off-by: David Ahern <dsahern@gmail.com>