netfilter: xt_NFLOG: use nf_log_packet instead of nfulnl_log_packet.

The nfulnl_log_packet() is added to make sure that the NFLOG target
works as only user-space logger. but now, nf_log_packet() can find proper
log function using NF_LOG_TYPE_ULOG and NF_LOG_TYPE_LOG.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>