BSD: When applying RA base information, ensure flags are correct
BSD: When applying RA base information, ensure flags are correct

For some resaon, under privsep only, SIOCGIFINFO_IN6 returns 0
in flags even though the kernel seems to set it correctly.
SIOCSIFINFO_IN6 *will* overwrite flags regardless, so ensure
it has the correct value for dhcpcd.

rsmarples/dhcpcd,rsmarples/dhcpcd,rsmarples/dhcpcd