[Fix] Fix C++ binding for fill_next_token_bitmask (#93)

This PR fixes the problem in fill_next_token_bitmask related to C++ binding.

python/xgrammar/matcher.py

@@ -204,7 +204,11 @@ def fill_next_token_bitmask(self, bitmask: torch.Tensor, index: int = 0) -> None
         index : int, default: 0
             The batch id of the bitmask.
         """
-        self._handle.fill_next_token_bitmask(bitmask, index)
+        if bitmask.device.type != "cpu":
+            raise ValueError("bitmask should be on CPU.")
+        if bitmask.dtype != bitmask_dtype:
+            raise ValueError(f"bitmask should be of type {bitmask_dtype}.")
+        self._handle.fill_next_token_bitmask(bitmask.data_ptr(), list(bitmask.shape), index)
 
     def find_jump_forward_string(self) -> str:
         """Find the jump-forward string for jump-forward decoding. This is the longest string that