fix backward in hgnet

Author: seefun

timm/models/hgnet.py

@@ -23,8 +23,8 @@ def __init__(self,
                  scale_value=1.0,
                  bias_value=0.0):
         super().__init__()
-        self.scale = nn.Parameter(torch.tensor([scale_value]))
-        self.bias = nn.Parameter(torch.tensor([bias_value]))
+        self.scale = nn.Parameter(torch.tensor([scale_value]), requires_grad=True)
+        self.bias = nn.Parameter(torch.tensor([bias_value]), requires_grad=True)
 
     def forward(self, x):
         return self.scale * x + self.bias
@@ -262,7 +262,7 @@ def forward(self, x):
         x = torch.cat(output, dim=1)
         x = self.aggregation(x)
         if self.residual:
-            x += identity
+            x = x + identity
         return x