ipv6: keep existing flags when setting IFA_F_OPTIMISTIC
ipv6: keep existing flags when setting IFA_F_OPTIMISTIC

Commit 64236f3f3d74 ("ipv6: introduce IFA_F_STABLE_PRIVACY flag")
failed to update the setting of the IFA_F_OPTIMISTIC flag, causing
the IFA_F_STABLE_PRIVACY flag to be lost if IFA_F_OPTIMISTIC is set.

Cc: Erik Kline <cbed88164a314c0a7942650afc8c70730ee0039f@google.com>
Cc: Fernando Gont <be839ef25d8531e33897896a543ea02b27c64287@si6networks.com>
Cc: Lorenzo Colitti <86995a091f8a1385082bd10715048b52ee386a6a@google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <843235c427d233c8a3c962f92f91acf3da14a1ed@miraclelinux.com>
Cc: Hannes Frederic Sowa <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@stressinduktion.org>
Fixes: 64236f3f3d74 ("ipv6: introduce IFA_F_STABLE_PRIVACY flag")
Signed-off-by: Bjørn Mork <8a2957e0063f2abf61bd145b6236a74a3708ac54@mork.no>
Acked-by: Hannes Frederic Sowa <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@stressinduktion.org>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs