fix_fpn_senet (#6791) (#6794)

ppdet/modeling/backbones/senet.py

@@ -16,6 +16,8 @@ import paddle.nn as nn
 
 from ppdet.core.workspace import register, serializable
 from .resnet import ResNet, Blocks, BasicBlock, BottleNeck
+from ..shape_spec import ShapeSpec
+from .name_adapter import NameAdapter
 
 __all__ = ['SENet', 'SERes5Head']
 

ppdet/modeling/necks/fpn.py

@@ -33,7 +33,7 @@ class FPN(nn.Layer):
     Args:
         in_channels (list[int]): input channels of each level which can be 
             derived from the output shape of backbone by from_config
-        out_channel (list[int]): output channel of each level
+        out_channel (int): output channel of each level
         spatial_scales (list[float]): the spatial scales between input feature
             maps and original input image which can be derived from the output 
             shape of backbone by from_config