fix lstm bug with peephole

Author: zhijxu-MS

tf2onnx/rewriter/lstm_rewriter.py

@@ -125,10 +125,14 @@ def _get_weight_and_bias_for_lstm_cell(self, context):
     def parse_attributes(self, context):
         if self.lstm_cell_type == RNNUnitType.LSTMBlockCell:
             lstm_block_cell = context.cell_match.get_op("lstm_block_cell")
-            clip = float(lstm_block_cell.get_attr("cell_clip").f)
+            clip = lstm_block_cell.get_attr_value("cell_clip")
             # current LSTM op cannot handle clip
             if clip > 0:
                 return False
+
+            use_peephole = lstm_block_cell.get_attr_value("use_peephole")
+            if use_peephole:
+                return False
         return True
 
     def _ct_variable_finder(self, context):