simplified get_hosts code to have 1 retrun point

lib/ansible/inventory/__init__.py

@@ -178,8 +178,7 @@ class Inventory(object):
             if self._restriction:
                 pattern_hash += u":%s" % to_unicode(self._restriction)
 
-        if pattern_hash in HOSTS_PATTERNS_CACHE:
-            return HOSTS_PATTERNS_CACHE[pattern_hash][:]
+        if pattern_hash not in HOSTS_PATTERNS_CACHE:
 
             patterns = Inventory.split_host_pattern(pattern)
             hosts = self._evaluate_patterns(patterns)
@@ -196,6 +195,7 @@ class Inventory(object):
                     hosts = [ h for h in hosts if h in self._restriction ]
 
             HOSTS_PATTERNS_CACHE[pattern_hash] = list(set(hosts))
+
         return HOSTS_PATTERNS_CACHE[pattern_hash][:]
 
     @classmethod