Remove one more pipe.
Remove one more pipe.

Re fixes #976
TBR=@alxandr

Review URL: https://github.com/google/traceur-compiler/pull/981

Closes #981, closes #976.

longze/traceur-compiler,rossberg-chromium/traceur-soundscript,bazaarvoice/traceur-compiler,pandoraui/traceur-compiler,google/traceur-compiler,mathiasbynens/traceur-compiler,johnjbarton/traceur-compiler,sebgod/traceur-compiler,arv/traceur-compiler,sebgod/traceur-compiler,astralfoxy/mirai-traceur,kittens/traceur-compiler,renie/traceur-compiler,sid0818/traceur-compiler,pandoraui/traceur-compiler,vicb/traceur-compiler,kittens/traceur-compiler,guybedford/traceur-compiler,google/traceur-compiler,lintangarief/traceur-compiler,sid0818/traceur-compiler,wilsonokibe/traceur-compiler,sebmck/traceur-compiler,bjlxj2008/traceur-compiler,longze/traceur-compiler,arv/traceur-compiler,sebmck/traceur-compiler,renie/traceur-compiler,vicb/traceur-compiler,rossberg-chromium/traceur-soundscript,lintangarief/traceur-compiler,johnjbarton/traceur-compiler,wilsonokibe/traceur-compiler,bazaarvoice/traceur-compiler,bjlxj2008/traceur-compiler