search: fix three tests in search_test.go.
search: fix three tests in search_test.go.

Change-Id: I578cd09d9c5082f08e0924be8796f3e431543e58

golang/appengine,fuchsia-mirror/third_party-github.com-golang-appengine,golang/appengine,fuchsia-mirror/third_party-github.com-golang-appengine