sweet: fix common.Go.Do call

CL 453502 changed the signature of Do, but this call site didn't get
updated.

Change-Id: I23223b45ecc27d7fe9fac589977cf3b5e2204d29
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/457395
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Michael Pratt <mpratt@google.com>
diff --git a/sweet/harnesses/go-build.go b/sweet/harnesses/go-build.go
index 3b3e278..33cc67b 100644
--- a/sweet/harnesses/go-build.go
+++ b/sweet/harnesses/go-build.go
@@ -93,7 +93,7 @@
 		return fmt.Errorf("error copying GOROOT: %v", err)
 	}
 	cfg.GoRoot = goroot
-	if err := cfg.GoTool().Do("install", "cmd/compile", "cmd/link"); err != nil {
+	if err := cfg.GoTool().Do("", "install", "cmd/compile", "cmd/link"); err != nil {
 		return fmt.Errorf("error building cmd/compile and cmd/link: %v", err)
 	}