[PKTGEN]: Adds missing __init.

pktgen_find_thread() and pktgen_create_thread() are only called at
initialization time.

Signed-off-by: Luiz Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/core/pktgen.c
Simple merge