Fix missed test in making org list fetcher static

Fixes error: `VCAP::CloudController::OrgListFetcher does not implement #fetch`

Follow up to 4858ee6, missed a test
when fixing things

[#173719526]

Authored-by: Sarah Weinstein <sweinstein@pivotal.io>

Author: sweinstein22

spec/unit/controllers/v3/organizations_controller_spec.rb

@@ -211,7 +211,7 @@
     end
 
     it 'eager loads associated resources that the presenter specifies' do
-      expect_any_instance_of(VCAP::CloudController::OrgListFetcher).to receive(:fetch).with(
+      expect(VCAP::CloudController::OrgListFetcher).to receive(:fetch).with(
         hash_including(eager_loaded_associations: [:labels, :annotations, :quota_definition])
       ).and_call_original