TypeError API exceptions get logged incorrectly

Fixes bug 942431

LOG.exception() always logs sys.exc_info() which does not always
represent the real exception we want to log.  This changes the wsgi
ResourceExceptionHandler context manager to LOG.error() the traeback
info that's passed to __exit__()

Change-Id: I0c3728a9ee740597feb828a513aea76e7849efc6

nova/api/openstack/wsgi.py

@@ -21,7 +21,6 @@ from xml.parsers import expat
 
 from lxml import etree
 import webob
-from webob import exc
 
 from nova import exception
 from nova import log as logging
@@ -574,7 +573,9 @@ class ResourceExceptionHandler(object):
             msg = unicode(ex_value)
             raise Fault(webob.exc.HTTPForbidden(explanation=msg))
         elif isinstance(ex_value, TypeError):
-            LOG.exception(ex_value)
+            exc_info = (ex_type, ex_value, ex_traceback)
+            LOG.error(_('Exception handling resource: %s') % ex_value,
+                    exc_info=exc_info)
             raise Fault(webob.exc.HTTPBadRequest())
         elif isinstance(ex_value, Fault):
             LOG.info(_("Fault thrown: %s"), unicode(ex_value))