cmd/gc: forgotten recursion on ninit itself in order.c
cmd/gc: forgotten recursion on ninit itself in order.c

Fixes test/reorder2.go for all cases tripped up with -lll in 5555072

R=rsc
CC=golang-dev
http://codereview.appspot.com/5569069

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang