As patch 'ip_gre: add the support for i/o_flags update via netlink'
did for netlink, we also need to do the same job for these update
via ioctl.

This patch is to update i/o_flags and call ipgre_link_update to
recalculate these gre properties after ip_tunnel_ioctl does the
common update.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>