Fix raptor bug. (#4192)

### What problem does this PR solve?


### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/nlp/search.py

@@ -383,8 +383,8 @@ class Dealer:
         res = []
         bs = 128
         for p in range(0, max_count, bs):
-            res = self.dataStore.search(fields, [], condition, [], OrderByExpr(), p, bs, index_name(tenant_id), kb_ids)
-            dict_chunks = self.dataStore.getFields(res, fields)
+            es_res = self.dataStore.search(fields, [], condition, [], OrderByExpr(), p, bs, index_name(tenant_id), kb_ids)
+            dict_chunks = self.dataStore.getFields(es_res, fields)
             if dict_chunks:
                 res.extend(dict_chunks.values())
             if len(dict_chunks.values()) < bs: