sweet/benchmarks/go-build: pass through stdout/stderr

In case systemd-run fails, we'd like to see the error in results.

For golang/go#54760.

Change-Id: Id19d938308d25cf37bbb9e129ce1ec9e89ac8726
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/426237
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/sweet/benchmarks/go-build/main.go b/sweet/benchmarks/go-build/main.go
index 2a77d44..1d72584 100644
--- a/sweet/benchmarks/go-build/main.go
+++ b/sweet/benchmarks/go-build/main.go
@@ -82,6 +82,8 @@
 	}
 	baseCmd.Dir = pkgPath
 	baseCmd.Env = common.NewEnvFromEnviron().MustSet("GOROOT=" + filepath.Dir(filepath.Dir(goTool))).Collapse()
+	baseCmd.Stdout = os.Stdout
+	baseCmd.Stderr = os.Stderr
 	cmd, err := cgroups.WrapCommand(baseCmd, "test.scope")
 	if err != nil {
 		return err