cmd/coordinator/buildongce: fix tests
cmd/coordinator/buildongce: fix tests

Fixes golang/go#26476

Change-Id: I380e47cfc0d51d0c297a2d7e5cdb263e09bcfd9c
Reviewed-on: https://go-review.googlesource.com/124975
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/build,golang/build,golang/build,golang/build