Fix missing reference titles in retrieval evaluation of RAG (#7817)

examples/rag/eval_rag.py

@@ -72,7 +72,7 @@ def get_precision_at_k(args, preds_path, gold_data_path):
     em = total = 0
     for hypo, reference in zip(hypos, references):
         hypo_provenance = set(hypo.split("\t")[:k])
-        ref_provenance = set(reference.split("\t")[1 : (k + 1)])
+        ref_provenance = set(reference.split("\t"))
         total += 1
         em += len(hypo_provenance & ref_provenance) / k