Polish code

python/paddle/fluid/layers/nn.py

@@ -6540,6 +6540,7 @@ for func in [
 def _logical_op(op_name, x, y, out=None, name=None, binary_op=True):
     helper = LayerHelper(op_name, **locals())
 
+    if binary_op:
         assert x.dtype == y.dtype
 
     if out is None: