fix gpu return (#664)

Author: Intron7

docs/release-notes/0.15.1.md

@@ -15,6 +15,7 @@
 
 ```{rubric} Misc
 ```
+* Tidy `_check_gpu_X` return value on the canonicalizing branch {pr}`xxx` {smaller}`S Dicks`
 * ``adata.uns[key_added]["params"]["resolution"]`` is now stored as a scalar ``float`` when a single resolution
 is passed to ``tl.leiden`` and ``tl.louvain`` to match behaviour in Scanpy, and as a ``list`` when multiple
 resolutions are passed. Previously it was always stored as a list. {pr}`648`. {smaller}`J Pintar`

src/rapids_singlecell/preprocessing/_utils.py

@@ -308,6 +308,7 @@ def _check_gpu_X(X, *, require_cf=False, allow_dask=False, allow_csc=True):
         else:
             X.sort_indices()
             X.sum_duplicates()
+            return True
     else:
         raise TypeError(
             "The input is not a CuPy ndarray or CuPy sparse matrix. "