exp/terminal: fix Makefile formatting for deps.bash

deps.bash does not understand current format,
so make.bash fails (with MAKEFLAGS=-j20).

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5410046

src/pkg/exp/terminal/Makefile

@@ -9,7 +9,8 @@ GOFILES=\
 	terminal.go\
 
 ifneq ($(GOOS),windows)
-GOFILES+=util.go
+GOFILES+=\
+	util.go
 endif
 
 include ../../../Make.pkg