Inserting rule before one with SET target we get error with warning in
dmesg(1) output:
# iptables -A FORWARD -t mangle -j SET --map-set test src --map-prio
# iptables -I FORWARD 1 -t mangle -j ACCEPT
iptables: Invalid argument. Run `dmesg' for more information.
# dmesg |tail -n1
[268578.026643] mapping of prio or/and queue is allowed only from \
OUTPUT/FORWARD/POSTROUTING chains
Rather than checking for supported hook bits for SET target check for
unsupported one as done in all rest of matches and targets.