cmd/updatestd: remove -d flag from go get invocation

The -d flag is deprecated and setting it to true is a no-op by now.
Removing it stops a warning from being printed when updatestd runs.

Change-Id: Ie123213919f0954240653f60060cadfed5adb8ae
Reviewed-on: https://go-review.googlesource.com/c/build/+/727440
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/cmd/updatestd/updatestd.go b/cmd/updatestd/updatestd.go
index b525533..ad57bfc 100644
--- a/cmd/updatestd/updatestd.go
+++ b/cmd/updatestd/updatestd.go
@@ -163,7 +163,7 @@
 	main, deps := buildList(dir)
 
 	// Determine module versions to get.
-	goGet := []string{goCmd, "get", "-d"}
+	goGet := []string{goCmd, "get"}
 	for _, m := range deps {
 		if !strings.HasPrefix(m.Path, "golang.org/x/") {
 			log.Printf("skipping %s (out of scope, it's not a golang.org/x dependency)\n", m.Path)