update Conv2D (#1594)

ppdet/modeling/backbone/darknet.py

@@ -20,7 +20,7 @@ class ConvBNLayer(nn.Layer):
                  name=None):
         super(ConvBNLayer, self).__init__()
 
-        self.conv = nn.Conv2d(
+        self.conv = nn.Conv2D(
             in_channels=ch_in,
             out_channels=ch_out,
             kernel_size=filter_size,

ppdet/modeling/head/yolo_head.py

@@ -128,7 +128,7 @@ class YOLOv3Head(nn.Layer):
             name = 'yolo_output.{}'.format(i)
             yolo_out = self.add_sublayer(
                 name,
-                nn.Conv2d(
+                nn.Conv2D(
                     in_channels=1024 // (2**i),
                     out_channels=num_filters,
                     kernel_size=1,