Changed variable name foo since it has been blacklisted in health

Tests/test_image_transform.py

@@ -128,13 +128,13 @@ class TestImageTransform(PillowTestCase):
         # Running by default, but I'd totally understand not doing it in
         # the future
 
-        foo = [
+        pattern = [
             Image.new('RGBA', (1024, 1024), (a, a, a, a))
             for a in range(1, 65)
         ]
 
         # Yeah. Watch some JIT optimize this out.
-        foo = None
+        pattern = None
 
         self.test_mesh()