[Fix] inconsistent dtype ofseg_label in stdc decode

mmseg/models/decode_heads/stdc_head.py

@@ -37,7 +37,7 @@ def losses(self, seg_logit, seg_label):
  # parameters. However, it is a constant in original repo and other
  # codebase because it would not be added into computation graph
  # after threshold operation.
- seg_label = seg_label.float()
+ seg_label = seg_label.to(self.laplacian_kernel)
  boundary_targets = F.conv2d(
  seg_label, self.laplacian_kernel, padding=1)
  boundary_targets = boundary_targets.clamp(min=0)