std: fix calls to Printf(s) with non-constant s

std: fix calls to Printf(s) with non-constant s

In all cases the intent was not to interpret s as a format string.
In one case (go/types), this was a latent bug in production.
(These were uncovered by a new check in vet's printf analyzer.)

Updates #60529

Change-Id: I3e17af7e589be9aec1580783a1b1011c52ec494b
Reviewed-on: https://go-review.googlesource.com/c/go/+/587855
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Russ Cox <rsc@golang.org>