Revert "netfilter: nft_hash: add map lookups for hashing operations"

mainline inclusion
from mainline-5.0
commit 0123a75e
category: bugfix
bugzilla: 11284
CVE: NA

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

A better way to implement this from userspace has been found without
specific code in the kernel side, revert this.

Fixes: b9ccc07e ("netfilter: nft_hash: add map lookups for hashing operations")
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Reviewed-by: Wenan Mao <maowenan@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>