netfilter: conntrack: avoid useless indirection during conntrack destruction

nf_ct_put() results in a usesless indirection:

nf_ct_put -> nf_conntrack_put -> nf_conntrack_destroy -> rcu readlock +
indirect call of ct_hooks->destroy().

There are two _put helpers:
nf_ct_put and nf_conntrack_put.  The latter is what should be used in
code that MUST NOT cause a linker dependency on the conntrack module
(e.g. calls from core network stack).

Everyone else should call nf_ct_put() instead.

A followup patch will convert a few nf_conntrack_put() calls to
nf_ct_put(), in particular from modules that already have a conntrack
dependency such as act_ct or even nf_conntrack itself.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Backport
6ae7989c ("netfilter: conntrack: avoid useless indirection during")
which is not going to stable tree from mainline to fix the following warning,
with some necessary context tweaks.

root@intel-x86-64:~# ovs-vsctl add-br br0
device ovs-system entered promiscuous mode
------------[ cut here ]------------
WARNING: CPU: 2 PID: 711 at include/net/netfilter/nf_conntrack.h:175 __ovs_ct_lookup+0x819/0x920 [openvswitch]
CPU: 2 PID: 711 Comm: ovs-vswitchd Not tainted 5.15.33-rt34-yocto-preempt-rt #1
Hardware name: Intel(R) Client Systems NUC7i5DNKE/NUC7i5DNB, BIOS DNKBLi5v.86A.0064.2019.0523.1933 05/23/2019
RIP: 0010:__ovs_ct_lookup+0x819/0x920 [openvswitch]
Code: b8 fe ff ff ff e9 69 f9 ff ff 41 0f b7 84 24 b0 00 00 00 49 8b 94 24 c0 00 00 00 0f b6 1c 02 83 e3 0f c1 e3 02 e9 c5 fc ff ff <0f> 0b e9 86 f8 ff ff 4c 89 f7 44 89 95 40 ff ff ff e8 61 30 fc ff
RSP: 0018:ffff914c80a77638 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff903b139fa528 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff914c80a77660 RDI: 0000000000000000
RBP: ffff914c80a77710 R08: ffff903b04819128 R09: ffffffffaa605c40
R10: ffff914c80a779c0 R11: 0000000000000000 R12: ffff903b05dd7000
R13: 0000000000000001 R14: ffff903b0a603c00 R15: ffff903b04819120
FS:  00007f9256c9ba80(0000) GS:ffff903c65d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe2fad9008 CR3: 000000010a5e0002 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? nf_ct_get_tuple+0x144/0x1f0 [nf_conntrack]
 ? nf_ct_get_tuplepr+0x5f/0x90 [nf_conntrack]
 ovs_ct_execute+0x3e1/0x5e0 [openvswitch]
 do_execute_actions+0xed/0x1ab0 [openvswitch]
 ? ovs_ct_copy_action+0x17b/0x8a0 [openvswitch]
 ? __ovs_nla_copy_actions+0x884/0xf30 [openvswitch]
 ? migrate_enable+0xd3/0x150
 ovs_execute_actions+0x62/0x140 [openvswitch]
 ? ovs_execute_actions+0x62/0x140 [openvswitch]
 ovs_packet_cmd_execute+0x294/0x310 [openvswitch]
 genl_family_rcv_msg_doit+0xe6/0x140
 genl_rcv_msg+0xde/0x1d0
 ? ovs_vport_cmd_del+0x200/0x200 [openvswitch]
 ? genl_get_cmd+0xd0/0xd0
 netlink_rcv_skb+0x55/0x100
 genl_rcv+0x29/0x40
 netlink_unicast+0x234/0x340
 netlink_sendmsg+0x226/0x470
 ? netlink_unicast+0x340/0x340
 ____sys_sendmsg+0x273/0x2b0
 ? sendmsg_copy_msghdr+0x7b/0xa0
 ___sys_sendmsg+0x81/0xc0
 ? do_futex+0x1c4/0xb70
 ? rt_spin_unlock+0x18/0x40
 ? __fget_light+0xa3/0x120
 __sys_sendmsg+0x62/0xb0
 ? fpregs_assert_state_consistent+0x27/0x50
 __x64_sys_sendmsg+0x1d/0x20
 do_syscall_64+0x43/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9256dab82d
Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 1a 97 f7 ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 44 24 08 e8 5e 97 f7 ff 48
RSP: 002b:00007ffe2fae90a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f9256dab82d
RDX: 0000000000000000 RSI: 00007ffe2fae9130 RDI: 0000000000000011
RBP: 00007ffe2fae9f30 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000006 R11: 0000000000000293 R12: 000055fab0216e90
R13: 0000000000000000 R14: 000055fab0216e90 R15: 00007ffe2fae9130
 </TASK>
---[ end trace 0000000000000002 ]---

Signed-off-by: He Zhe <zhe.he@windriver.com>

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>