[doc prepare_seq2seq_batch] fix docs (#8013)

src/transformers/tokenization_bart.py

@@ -122,7 +122,7 @@ class BartTokenizer(RobertaTokenizer):
             - **attention_mask** -- List of indices specifying which tokens should be attended to by the model.
             - **labels** -- List of token ids for tgt_texts
 
-            The full set of keys ``[input_ids, attention_mask, decoder_input_ids,  decoder_attention_mask]``,
+            The full set of keys ``[input_ids, attention_mask, labels]``,
             will only be returned if tgt_texts is passed. Otherwise, input_ids, attention_mask will be the only keys.
         """
         kwargs.pop("src_lang", None)

src/transformers/tokenization_utils_base.py

@@ -1364,11 +1364,9 @@ PREPARE_SEQ2SEQ_BATCH_DOCSTRING = """
 
             - **input_ids** -- List of token ids to be fed to the encoder.
             - **attention_mask** -- List of indices specifying which tokens should be attended to by the model.
-            - **decoder_input_ids** -- List of token ids to be fed to the decoder.
-            - **decoder_attention_mask** -- List of indices specifying which tokens should be attended to by the decoder.
-                This does not include causal mask, which is built by the model.
+            - **labels** -- List of token ids for tgt_texts.
 
-            The full set of keys ``[input_ids, attention_mask, decoder_input_ids,  decoder_attention_mask]``,
+            The full set of keys ``[input_ids, attention_mask, labels]``,
             will only be returned if tgt_texts is passed. Otherwise, input_ids, attention_mask will be the only keys.
 
 """