Description: cgroup: fix cgroup_sk_alloc() for sk_clone_lock()
References:
 https://bugzilla.kernel.org/show_bug.cgi?id=208003
 https://lore.kernel.org/netdev/CAM_iQpUKQJrj8wE+Qa8NGR3P0L+5Uz=qo-O5+k_P60HzTde6aw%40mail.gmail.com/t/
 https://bugzilla.redhat.com/show_bug.cgi?id=1868453
Notes:
Bugs:
 966846
upstream: released (5.8-rc5) [ad0f75e5f57ccbceec13274e1e242f2b5a6397ed]
4.19-upstream-stable: released (4.19.134) [0505cc4c908f46a4d22c4994dbbe7bc489d0c52d]
4.9-upstream-stable: released (4.9.231) [51fbad61b1dc2a082c7f7dbc3b1299a1e40c061a]
sid: released (5.7.10-1)
4.19-buster-security: needed
4.9-stretch-security: needed