Fix incorrect `let` in pipeline metrics worker specs

spec/workers/pipeline_metrics_worker_spec.rb

@@ -2,7 +2,12 @@ require 'spec_helper'
 
 describe PipelineMetricsWorker do
   let(:project) { create(:project, :repository) }
-  let!(:merge_request) { create(:merge_request, source_project: project, source_branch: pipeline.ref, head_pipeline: pipeline) }
+
+  let!(:merge_request) do
+    create(:merge_request, source_project: project,
+                           source_branch: pipeline.ref,
+                           head_pipeline: pipeline)
+  end
 
   let(:pipeline) do
     create(:ci_empty_pipeline,
@@ -14,6 +19,8 @@ describe PipelineMetricsWorker do
            finished_at: Time.now)
   end
 
+  let(:status) { 'pending' }
+
   describe '#perform' do
     before do
       described_class.new.perform(pipeline.id)