Revert "cmd/vet: ignore printf failures in cmd"

This reverts commit f15915af.

CL 32851 fixed cmd/vet's handling of fmt.Formatter.

Updates #17057.

Change-Id: I3409100d16037645946fe7fe78fbb173e1648494
Reviewed-on: https://go-review.googlesource.com/33166
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/vet/all/main.go

@@ -265,15 +265,6 @@ NextLine:
 			}
 		}
 
-		// Temporarily ignore unrecognized printf verbs from cmd.
-		// The compiler now has several fancy verbs (CL 28339)
-		// used with types implementing fmt.Formatters,
-		// and I believe gri has plans to add many more.
-		// TODO: remove when issue 17057 is fixed.
-		if strings.HasPrefix(file, "cmd/") && strings.HasPrefix(msg, "unrecognized printf verb") {
-			continue
-		}
-
 		key := file + ": " + msg
 		if w[key] == 0 {
 			// Vet error with no match in the whitelist. Print it.