datapath/actions: Mark recalculate_csum as likely in set_ipv6_addr().

The ‘recalculate_csum’ is almost always ‘true’.  It is false only if
the ipv6 nexthdr is an extension header, and a routing header is
found.  For the majority of ipv6 packets this would not be the case,
so this can be marked as 'likely'.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
datapath/flow_netlink: Validate IPv6 flow key and mask values.

Reject flow label key and mask values with invalid bits set.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>