Getting negative host pattern matching to work with external inventory

(same as commit 4caf85e37b, but for
excluded hosts as well as subsets)

lib/ansible/inventory/__init__.py

@@ -109,8 +109,8 @@ class Inventory(object):
 
         # exclude hosts mentioned in a negative pattern
         if len(negative_patterns):
-            exclude_hosts = self._get_hosts(negative_patterns)
-            hosts = [ h for h in hosts if h not in exclude_hosts ]
+            exclude_hosts = [ h.name for h in self._get_hosts(negative_patterns) ]
+            hosts = [ h for h in hosts if h.name not in exclude_hosts ]
 
         # exclude hosts not in a subset, if defined
         if self._subset: