ipautil.run, kernel_keyring: Encoding fixes for Python 3

https://fedorahosted.org/freeipa/ticket/5638

Reviewed-By: Jan Cholasta <jcholast@redhat.com>

ipatests/test_ipapython/test_ipautil.py

@@ -444,7 +444,7 @@ def test_run_no_capture_output():
 def test_run_bytes():
     result = ipautil.run(['echo', b'\x01\x02'], capture_output=True)
     assert result.returncode == 0
-    assert result.output == b'\x01\x02\n'
+    assert result.raw_output == b'\x01\x02\n'
 
 
 def test_run_decode():