fix _X which raises error when view

Author: falexwolf

anndata/_core/anndata.py

@@ -1192,7 +1192,7 @@ def _inplace_subset_obs(self, index: Index1D):
         Same as `adata = adata[index, :]`, but inplace.
         """
         adata_subset = self[index].copy()
-        self._init_as_actual(adata_subset, dtype=self._X.dtype)
+        self._init_as_actual(adata_subset, dtype=self.X.dtype)
 
     # TODO: Update, possibly remove
     def __setitem__(