linuxolator: add netlink support

[melifaro]

Summary

Compat part for running Linux binaries with Netlink ( D36002 ).

Test Plan

Please see testing section in D36002.

[melifaro]

Update to recent -HEAD.

[dchagin]

mostly style, thank you! tested with 2.35 glibc tests suite, inet tests completed!

sys/compat/linux/linux_netlink.c

32

I suggest to add an empty line here

61

style, blank line, and in many functions below

121

unnecessary parentheses

131

the same here

167

may be use return (netlink_family != NETLINK_ROUTE ? hdr :
rtnl_from_linux(hdr, npt));
?

184

blank line

186

if (out_hdr != NULL)

		memcpy(out_hdr, hdr, hdr->nlmsg_len);

return (out_hdr != NULL);

?

219

the same as above

235

unnecessary parentheses

386

unnecessary parentheses

[melifaro]

Update to reflect netlink KPI changes.