cmd/vet/all: update whitelist

CL 29110 brought the fix into the main tree.

Change-Id: I7bf02670d40f22d35c63e05173419fdee9f93462
Reviewed-on: https://go-review.googlesource.com/29161
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/vet/all/whitelist/all.txt

 // Non-platform-specific vet whitelist. See readme.txt for details.
 
-// Issue 16228. Fixed, just waiting for an http2 re-vendor.
-net/http/h2_bundle.go: assignment copies lock value to *cfg: crypto/tls.Config contains sync.Once contains sync.Mutex
-
-
 // Real problems that we can't fix.
 
 // This is a bad WriteTo signature. Errors are being ignored!