Revert "xfrm: state and policy should fail if XFRMA_IF_ID 0"

stable inclusion
from linux-4.19.236
commit c8c9220cc0fb0dcdcce140533cc46128bd836347
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5646A
CVE: NA

--------------------------------

commit a3d9001b upstream.

This reverts commit 68ac0f38 because ID
0 was meant to be used for configuring the policy/state without
matching for a specific interface (e.g., Cilium is affected, see
https://github.com/cilium/cilium/pull/18789 and
https://github.com/cilium/cilium/pull/19019

).

Signed-off-by: Kai Lueke <kailueke@linux.microsoft.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>