Constraint FindReviews with condition

On the LatestOnly subquery, re-use the outter condition to avoid always
grouping by all reviews in the database.

Signed-off-by: Cory Todd <cory.todd@canonical.com>

models/issues/pull_test.go

@@ -336,4 +336,4 @@ func TestGetApprovers(t *testing.T) {
 	approvers := pr.GetApprovers()
 	expected := "Reviewed-by: User Five <user5@example.com>\nReviewed-by: User Six <user6@example.com>\n"
 	assert.EqualValues(t, expected, approvers)
-}
+}

models/issues/review.go

@@ -266,14 +266,16 @@ func (opts *FindReviewOptions) toCond() builder.Cond {
 // FindReviews returns reviews passing FindReviewOptions
 func FindReviews(ctx context.Context, opts FindReviewOptions) ([]*Review, error) {
 	reviews := make([]*Review, 0, 10)
-	sess := db.GetEngine(ctx).Where(opts.toCond())
+	cond := opts.toCond()
+	sess := db.GetEngine(ctx).Where(cond)
 	if opts.Page > 0 {
 		sess = db.SetSessionPagination(sess, &opts)
 	}
 	if opts.LatestOnly {
 		sess.In("id", builder.
 			Select("max ( id ) ").
 			From("review").
+			Where(cond).
 			GroupBy("reviewer_id"))
 	}
 	return reviews, sess.