[release-branch.go1.7] static: don't use the jQuery func for looking up based on hash

$.find is safer.

Change-Id: I51893b64ce804ac5a70f780a1255af2c91413110
Reviewed-on: https://go-review.googlesource.com/35430
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-on: https://go-review.googlesource.com/35431
Reviewed-by: Chris Broadfoot <cbro@golang.org>
diff --git a/godoc/static/godocs.js b/godoc/static/godocs.js
index 3472452..8f9ed25 100644
--- a/godoc/static/godocs.js
+++ b/godoc/static/godocs.js
@@ -247,7 +247,7 @@
 function toggleHash() {
   // Open all of the toggles for a particular hash.
   var els = $(document.getElementById(window.location.hash.substring(1)),
-      $("a[name='" + window.location.hash.substring(1) + "']"));
+      $.find("a[name='" + window.location.hash.substring(1) + "']"));
   while (els.length) {
     for (var i = 0; i < els.length; i++) {
       var el = $(els[i]);