Fix canny import test

skimage/filters/tests/test_deprecated_imports.py

@@ -1,4 +1,6 @@
 from warnings import catch_warnings, simplefilter
+from ..._shared._warnings import expected_warnings
+from ...data import moon
 
 
 def test_filter_import():
@@ -11,9 +13,7 @@ def test_filter_import():
 
 
 def test_canny_import():
-    with catch_warnings():
-        simplefilter('ignore')
+    data = moon()
+    with expected_warnings(['skimage.feature.canny']):
         from skimage.filters import canny
-
-    assert('canny' in dir(F))
-    assert F._import_warned
+        canny(data)