testing: fix wording in explanation of potential bug TBR=rsc
testing: fix wording in explanation of potential bug
TBR=rsc

R=rsc
CC=golang-dev
http://codereview.appspot.com/5504075

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