Enable CPU execution of RandomForestRegressor.score

Author: jcrist

python/cuml/cuml/ensemble/randomforestregressor.pyx

@@ -629,6 +629,7 @@ class RandomForestRegressor(BaseRandomForestModel,
         domain="cuml_python")
     @insert_into_docstring(parameters=[('dense', '(n_samples, n_features)'),
                                        ('dense', '(n_samples, 1)')])
+    @enable_device_interop
     def score(self, X, y, algo='auto', convert_dtype=True,
               fil_sparse_format='auto', predict_model="GPU"):
         """

python/cuml/cuml_accel_tests/integration/test_rf_regressor.py

@@ -48,7 +48,10 @@ def test_rf_criterion_reg(regression_data, criterion):
         criterion=criterion, n_estimators=50, random_state=42
     )
     reg.fit(X, y)
-    _ = r2_score(y, reg.predict(X))
+    score1 = r2_score(y, reg.predict(X))
+    assert isinstance(score1, float)
+    score2 = reg.score(X, y)
+    assert isinstance(score2, float)
 
 
 @pytest.mark.parametrize("max_depth", [None, 5, 10])