ipvs: fix memory leak in ip_vs_ctl.c

Fix memory leak introduced in commit a0840e2e165a ("IPVS: netns,
ip_vs_ctl local vars moved to ipvs struct."):

unreferenced object 0xffff88005785b800 (size 2048):
comm "(-localed)", pid 1434, jiffies 4294755650 (age 1421.089s)
hex dump (first 32 bytes):
bb 89 0b 83 ff ff ff ff b0 78 f0 4e 00 88 ff ff .........x.N....
04 00 00 00 a4 01 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff8262ea8e>] kmemleak_alloc+0x4e/0xb0
[<ffffffff811fba74>] __kmalloc_track_caller+0x244/0x430
[<ffffffff811b88a0>] kmemdup+0x20/0x50
[<ffffffff823276b7>] ip_vs_control_net_init+0x1f7/0x510
[<ffffffff8231d630>] __ip_vs_init+0x100/0x250
[<ffffffff822363a1>] ops_init+0x41/0x190
[<ffffffff82236583>] setup_net+0x93/0x150
[<ffffffff82236cc2>] copy_net_ns+0x82/0x140
[<ffffffff810ab13d>] create_new_namespaces+0xfd/0x190
[<ffffffff810ab49a>] unshare_nsproxy_namespaces+0x5a/0xc0
[<ffffffff810833e3>] SyS_unshare+0x173/0x310
[<ffffffff8265cbd7>] system_call_fastpath+0x12/0x6f
[<ffffffffffffffff>] 0xffffffffffffffff

Fixes: a0840e2e165a ("IPVS: netns, ip_vs_ctl local vars moved to ipvs struct.")
Signed-off-by: Tommi Rantala <[e-mail]>
Acked-by: Julian Anastasov <[e-mail]>
Signed-off-by: Simon Horman <[e-mail]>

net/netfilter/ipvs/ip_vs_ctl.c

···
 	cancel_work_sync(&ipvs->defense_work.work);
 	unregister_net_sysctl_table(ipvs->sysctl_hdr);
 	ip_vs_stop_estimator(net, &ipvs->tot_stats);
+
+	if (!net_eq(net, &init_net))
+		kfree(ipvs->sysctl_tbl);
 }
 
 #else