fix jit bug

Author: rusty1s

torch_cluster/radius.py

@@ -7,7 +7,7 @@
 @torch.jit.script
 def sample(col: torch.Tensor, count: int) -> torch.Tensor:
     if col.size(0) > count:
-        col = col[torch.randperm(col.size(0))][:count]
+        col = col[torch.randperm(col.size(0), dtype=torch.long)][:count]
     return col