cmd/dist: make test names consistent

cmd/dist: make test names consistent

Current banners are:

##### Building Go bootstrap tool.
##### Building Go toolchain using /Users/josh/go/1.4.
##### Building go_bootstrap for host, darwin/amd64.
##### Building packages and commands for darwin/amd64.
##### Testing packages.
##### GOMAXPROCS=2 runtime -cpu=1,2,4
##### Testing without libgcc.
##### sync -cpu=10
##### ../misc/cgo/stdio
##### ../misc/cgo/life
##### ../misc/cgo/fortran
##### ../misc/cgo/test
##### Testing race detector
##### ../misc/cgo/testso
##### ../misc/cgo/testsovar
##### misc/cgo/testcarchive
##### ../misc/cgo/testcshared
##### ../misc/cgo/errors
##### ../test/bench/go1
##### ../test
##### API check

One of these things is not like the others.
Fix that.

Change-Id: If0bd8ea9293d73b5d1b70d6bf676bd9192991505
Reviewed-on: https://go-review.googlesource.com/26759
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>