Revert change in SDPX tests XML loading

The ways of XML and encoding are sometimes complex.

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

tests/formattedcode/test_output_spdx.py

@@ -122,7 +122,9 @@ def check_rdf_scan(expected_file, result_file, regen=False):
         with io.open(expected_file, 'w', encoding='utf-8') as o:
             json.dump(result, o, indent=2)
     else:
-        expected = load_and_clean_rdf(expected_file)
+        with io.open(expected_file, encoding='utf-8') as i:
+            expected = json.load(i)
+            expected = load_and_clean_rdf(result_file)
 
     assert json.dumps(result, indent=2) == json.dumps(expected, indent=2)