doc: fix typo in Go for C++ programmers
doc: fix typo in Go for C++ programmers

R=iant
CC=golang-dev
http://codereview.appspot.com/5555062

Committer: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

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