Revert "Raise an AccessError with SessionService init"

This reverts commit a2096cd302.

Reason for revert: This creates a regression in fallback to guessing a path for creating session initialization, and the underlying failure was not actually causing an AttributeError to be raised but was still silently being consumed. It seems the right fix is a bit more involved and for the sake of cleanliness, reverting this patch.

Change-Id: I04321b004fae5a6ae45996b83b817c2257e24f7b

releasenotes/notes/session-authenication-now-raises-exception-64c5e62c1775e653.yaml

@@ -1,7 +0,0 @@
----
-fixes:
-  - |
-    Fixes an issue where stale or invalid authentication data may
-    result in an attempt to lookup the ``SessionService`` failing
-    without any exception. The failure will now raise an
-    ``AccessError`` exception.

sushy/resources/sessionservice/sessionservice.py

@@ -54,7 +54,6 @@ class SessionService(base.ResourceBase):
         :param registries: Dict of Redfish Message Registry objects to be
             used in any resource that needs registries to parse messages
         :param root: Sushy root object. Empty for Sushy root itself.
-        :raises: AccessError if resource authentication fails.
         """
         try:
             super(SessionService, self).__init__(
@@ -66,7 +65,6 @@ class SessionService(base.ResourceBase):
                       'SessionService. If this happens before '
                       'authentication, we\'ll have to guess the Sessions URL.',
                       ae)
-            raise
 
     def _get_sessions_collection_path(self):
         """Helper function to find the SessionCollections path"""

sushy/tests/unit/resources/sessionservice/test_sessionservice.py

@@ -43,11 +43,7 @@ class SessionServiceTestCase(base.TestCase):
         self.conn.get.return_value.json.side_effect = (
             exceptions.AccessError(
                 'GET', 'any_url', mock.MagicMock()))
-        # Actually, it is a good thing to raise access error exceptions,
-        # so we know when we need to handle failures.
-        self.assertRaises(
-            exceptions.AccessError,
-            sessionservice.SessionService,
+        sessionservice.SessionService(
             self.conn, '/redfish/v1/SessionService', redfish_version='1.0.2')
         self.assertTrue(mock_LOG.debug.called)