godoc: remove dependency of syscall
godoc: remove dependency of syscall

On app-engine, we cannot import syscall.
The respective constants are already defined
elsewhere for the same reason.

R=r, dsymonds
CC=golang-dev
http://codereview.appspot.com/5036042
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go