ipv6 addrconf: revert /proc/net/if_inet6 ifa_flag format
ipv6 addrconf: revert /proc/net/if_inet6 ifa_flag format

Turned out that applications like ifconfig do not handle the change.
So revert ifa_flag format back to 2-letter hex value.

Introduced by:
commit 479840ffdbe4242e8a25349218c8e0859223aa35
    "ipv6 addrconf: extend ifa_flags to u32"

Reported-by: Alexander Aring <d03dbcdedb9639e397df9b8578e8fc8274f4e6c4@gmail.com>
Signed-off-by: Jiri Pirko <1b548d10035ae428195c41f5d55eedb1437ccd8a@resnulli.us>
Tested-by: FLorent Fourcot <787ae617617698b2b89c353cdfb3f2e4d16ffeb7@enst-bretagne.fr>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

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