netfilter: nf_tables: fix underflow in chain reference counter

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix underflow in chain reference counter Set element addition error path decrements reference counter on chains twice: once on element release and again via nft_data_release(). Then, d6b478666ffa ("netfilter: nf_tables: fix underflow in object reference counter") incorrectly fixed this by removing the stateful object reference count decrement. Restore the stateful object decrement as in b91d90368837 ("netfilter: nf_tables: fix leaking object reference count") and let nft_data_release() decrement the chain reference counter, so this is done only once.