os/stat_freebsd.go: maybe fix build for freebsd
os/stat_freebsd.go: maybe fix build for freebsd

R=rsc
CC=golang-dev
http://codereview.appspot.com/970042
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go