Improve MergeRequest#head_pipeline

app/models/merge_request.rb

@@ -146,11 +146,7 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def head_pipeline
-    return unless head_pipeline_id
-
-    last_pipeline = Ci::Pipeline.find(head_pipeline_id)
-
-    last_pipeline.sha == diff_head_sha ? last_pipeline : nil
+    super&.sha == diff_head_sha ? super : nil
   end
 
   # Pattern used to extract `!123` merge request references from text