Fix lint errors.

cmd/pullrequest-init/fake_github.go

@@ -168,7 +168,7 @@ func (g *FakeGitHub) updateComment(w http.ResponseWriter, r *http.Request) {
 
 	existing, ok := g.comments[key]
 	if !ok {
-		http.Error(w, err.Error(), http.StatusNotFound)
+		http.Error(w, fmt.Sprintf("comment %+v not found", key), http.StatusNotFound)
 		return
 	}
 
@@ -191,7 +191,7 @@ func (g *FakeGitHub) deleteComment(w http.ResponseWriter, r *http.Request) {
 	// Remove comment from PR storage. Not particularly efficient, but we don't
 	// generally expect this to be used for large number of comments in unit
 	// tests.
-	for k, _ := range g.prComments {
+	for k := range g.prComments {
 		for i, c := range g.prComments[k] {
 			if c.GetID() == key.id {
 				g.prComments[k] = append(g.prComments[k][:i], g.prComments[k][i+1:]...)