include/resolv.h: provide __res_state._u even if !__UCLIBC_HAS_IPV6__
include/resolv.h: provide __res_state._u even if !__UCLIBC_HAS_IPV6__

This struct is used for IPv4 as well, so only make the members
conditional that are purely used by IPv6.

Signed-off-by: Daniel Mack <70806a71956ed8873ecff8522779dae1401a1b4a@gmail.com>

joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc