[NETFILTER]: nfnetlink_{queue,log}: return proper error codes in instance_create

Currently we return EINVAL for "instance exists", "allocation failed" and
"module unloaded below us", which is completely inapproriate.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/netfilter/nfnetlink_log.c
Simple merge

diff --cc net/netfilter/nfnetlink_queue.c
Simple merge