fix: Inconsistent single-channel expansion between loss components

Signed-off-by: ytl0623 <[email protected]>

Author: ytl0623

monai/losses/unified_focal_loss.py

@@ -172,7 +172,7 @@ def forward(self, y_pred: torch.Tensor, y_true: torch.Tensor) -> torch.Tensor:
             y_true: ground truth labels.
         """
 
-        if y_pred.shape[1] == 1 and not self.use_softmax:
+        if y_pred.shape[1] == 1:
             y_pred = torch.sigmoid(y_pred)
             y_pred = torch.cat([1 - y_pred, y_pred], dim=1)
             is_already_prob = True