crypto/ssh: update references to the old code.google.com repo

Changed code.google.com repository links to the current
golang.org/x/crypto/ssh (except Gerrit homepage).

Change-Id: I7301d21401b163ceef8cfc1cf535dee998f9cb0d
Reviewed-on: https://go-review.googlesource.com/9250
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

ssh/test/doc.go

@@ -3,5 +3,5 @@
 // license that can be found in the LICENSE file.
 
 // This package contains integration tests for the
-// code.google.com/p/go.crypto/ssh package.
+// golang.org/x/crypto/ssh package.
 package test // import "golang.org/x/crypto/ssh/test"

ssh/testdata/doc.go

@@ -3,6 +3,6 @@
 // license that can be found in the LICENSE file.
 
 // This package contains test data shared between the various subpackages of
-// the code.google.com/p/go.crypto/ssh package. Under no circumstance should
+// the golang.org/x/crypto/ssh package. Under no circumstance should
 // this data be used for production code.
 package testdata // import "golang.org/x/crypto/ssh/testdata"