misc: update zsh completion
misc: update zsh completion

R=golang-dev, minux.ma
CC=golang-dev
https://codereview.appspot.com/8437043

Committer: Shenghou Ma <b563c57947dc20eb81988e3e3c22786764c14ca8@gmail.com>

apparentlymart/golang,dsriram/golang,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,tv42/old-go,dsriram/golang,dsriram/golang,gnanderson/go,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,gnanderson/go,apparentlymart/golang,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,gnanderson/go,apparentlymart/golang,dsriram/golang,gnanderson/go,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,gnanderson/go,gnanderson/go,tv42/old-go,apparentlymart/golang,apparentlymart/golang,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,dsriram/golang,apparentlymart/golang,pombredanne/go-deleteme