Update lightweight.py

Author: 545999961

FlagEmbedding/inference/reranker/decoder_only/lightweight.py

@@ -435,7 +435,7 @@ def compute_score_single_gpu(
             if normalize:
                 all_scores[i] = [sigmoid(score) for score in all_scores[i]]
 
-        if isinstance(all_scores[0], list):
+        if len(all_scores) == 1 and isinstance(all_scores[0], list):
             all_scores = all_scores[0]
 
         return all_scores