Wrong timeout variable for inbound TCP/UDP state cleanup: 6x/3x premature expiry

Summary

nat_cleanup_func_dispatch: inbound TCP states(:971) checked against sysctl_var_icmp_timeout(default 10s) instead of sysctl_var_tcp_timeout(60s). Inbound UDP states(:989) checked against icmp_timeout instead of udp_timeout(30s). Same in ip_fw3_ctl_nat_get_record(:632/:688). Inbound entries vanish 6x/3x faster than configured breaking idle TCP connections NAT mappings. Fix: use tcp_timeout at :971/:632 udp_timeout at :989/:688.