bpo-37964: Make sure test works if TESTFN is in a non-ASCII directory. (GH-15568)

diff --git a/Lib/test/test_fcntl.py b/Lib/test/test_fcntl.py
index 38097db..a2b5997 100644
--- a/Lib/test/test_fcntl.py
+++ b/Lib/test/test_fcntl.py
@@ -147,9 +147,9 @@
     @unittest.skipIf(sys.platform != 'darwin', "F_GETPATH is only available on macos")
     def test_fcntl_f_getpath(self):
         self.f = open(TESTFN, 'wb')
-        abspath = os.path.abspath(TESTFN)
-        res = fcntl.fcntl(self.f.fileno(), fcntl.F_GETPATH, bytes(len(abspath)))
-        self.assertEqual(abspath, res.decode('utf-8'))
+        expected = os.path.abspath(TESTFN).encode('utf-8')
+        res = fcntl.fcntl(self.f.fileno(), fcntl.F_GETPATH, bytes(len(expected)))
+        self.assertEqual(expected, res)
 
 def test_main():
     run_unittest(TestFcntl)