doc/faq: replace reference to goven with gomvpkg

github.com/kr/goven says it's deprecated and anyway
it would be preferable to point users to a standard Go tool.

Change-Id: Iac4a0d13233604a36538748d498f5770b2afce19
Reviewed-on: https://go-review.googlesource.com/8969Reviewed-by: Minux Ma <minux@golang.org>

doc/go_faq.html

@@ -1046,7 +1046,7 @@ unexpected ways, the simplest solution is to copy it to your local repository.
 (This is the approach Google takes internally.)
 Store the copy under a new import path that identifies it as a local copy.
 For example, you might copy "original.com/pkg" to "you.com/external/original.com/pkg".
-Keith Rarick's <a href="https://github.com/kr/goven">goven</a> is one tool to help automate this process.
+<a href="https://godoc.org/golang.org/x/tools/cmd/gomvpkg">gomvpkg</a> is one tool to help automate this process.
 </p>
 
 <h2 id="Pointers">Pointers and Allocation</h2>