polish some useless code (#50533)

python/paddle/tensor/creation.py

@@ -1344,7 +1344,7 @@ def tril(x, diagonal=0, name=None):
             #         [9 , 10, 0 , 0 ]])
     """
     if in_dygraph_mode():
-        return _C_ops.tril(x, diagonal, True)
+        return _C_ops.tril(x, diagonal)
     else:
         return _tril_triu_op(LayerHelper('tril', **locals()))
 
@@ -1406,7 +1406,7 @@ def triu(x, diagonal=0, name=None):
 
     """
     if in_dygraph_mode():
-        return _C_ops.triu(x, diagonal, False)
+        return _C_ops.triu(x, diagonal)
     else:
         return _tril_triu_op(LayerHelper('triu', **locals()))
 

python/paddle/tensor/math.py

@@ -4677,10 +4677,7 @@ def diff(x, n=1, axis=-1, prepend=None, append=None, name=None):
                 outputs={"Out": out},
             )
         else:
-            out = paddle.tensor.math._subtract_with_axis(
-                input_back, input_front, axis=axis
-            )
-
+            out = paddle.tensor.math.subtract(input_back, input_front)
         return out