Correctly release ipa-reference summarries

[Jan Hubicka]

Hi,
this patch fixes code removing summaries in ipa-reference.  As a memory
leak it may make sense to backport this to release branches.

Honza

        * ipa-reference.c (propagate): Fix releasing of IPA summaries.
Index: ipa-reference.c
===================================================================
--- ipa-reference.c     (revision 276707)
+++ ipa-reference.c     (working copy)
@@ -891,15 +889,14 @@ propagate (void)
 
   bitmap_obstack_release (&local_info_obstack);
 
-  if (ipa_ref_var_info_summaries == NULL)
+  if (ipa_ref_var_info_summaries != NULL)
     {
       delete ipa_ref_var_info_summaries;
       ipa_ref_var_info_summaries = NULL;
     }
 
-  ipa_ref_var_info_summaries = NULL;
   if (dump_file)
     splay_tree_delete (reference_vars_to_consider);
   reference_vars_to_consider = NULL;
   return remove_p ? TODO_remove_functions : 0;
 }