Yakkety update to v4.8.14 stable release

SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from a mainline/stable Linux tree or
       a minimally backported form of that patch. The v4.8.14 upstream stable
       patch set is now available. It should be included in the Ubuntu
       kernel as well.

       git://git.kernel.org/

    TEST CASE: TBD

       The following patches from the v4.8.14 stable release shall be applied:

gro_cells: mark napi struct as not busy poll candidates
virtio-net: add a missing synchronize_net()
net: dsa: b53: Fix VLAN usage and how we treat CPU port
net: check dead netns for peernet2id_alloc()
ip6_tunnel: disable caching when the traffic class is inherited
net: sky2: Fix shutdown crash
af_unix: conditionally use freezable blocking calls in read
rtnetlink: fix FDB size computation
l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind()
rtnl: fix the loop index update error in rtnl_dump_ifinfo()
ipv6: bump genid when the IFA_F_TENTATIVE flag is clear
udplite: call proper backlog handlers
net: dsa: bcm_sf2: Ensure we re-negotiate EEE during after link change
net, sched: respect rcu grace period on cls destruction
net: dsa: fix unbalanced dsa_switch_tree reference counting
net/sched: pedit: make sure that offset is valid
netlink: Call cb->done from a worker thread
netlink: Do not schedule work from sk_destruct
net: macb: fix the RX queue reset in macb_rx()
net/dccp: fix use-after-free in dccp_invalid_packet
GSO: Reload iph after pskb_may_pull
ip6_offload: check segs for NULL in ipv6_gso_segment.
cdc_ether: Fix handling connection notification
net: bcmgenet: Utilize correct struct device for all DMA operations
sh_eth: remove unchecked interrupts for RZ/A1
tipc: check minimum bearer MTU
geneve: avoid use-after-free of skb->data
net: ping: check minimum size on ICMP header length
ipv4: Restore fib_trie_flush_external function and fix call ordering
ipv4: Fix memory leak in exception case for splitting tries
ipv4: Drop leaf from suffix pull/push functions
ipv4: Drop suffix update from resize code
sparc64: Fix find_node warning if numa node cannot be found
sparc64: fix compile warning section mismatch in find_node()
sparc32: Fix inverted invalid_frame_pointer checks on sigreturns
constify iov_iter_count() and iter_is_iovec()
Don't feed anything but regular iovec's to blk_rq_map_user_iov
ipv6: Set skb->protocol properly for local output
ipv4: Set skb->protocol properly for local output
Revert: "ip6_tunnel: Update skb->protocol to ETH_P_IPV6 in ip6_tnl_xmit()"
flowcache: Increase threshold for refusing new allocations
esp4: Fix integrity verification when ESN are used
esp6: Fix integrity verification when ESN are used
Linux 4.8.14