Solve a modulus rounding error. As the modulus can be signed (in C89 it take

the sign of the divident), we have to cast the pointer to an uintptr_t in
order to be able to correctly compute how to align it on the cache line.
Rported and solved by Stephan Kramer. Thanks Stephan.

This commit was SVN r19778.

opal/class/opal_free_list.c

@@ -2,7 +2,7 @@
  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
  *                         Corporation.  All rights reserved.
- * Copyright (c) 2004-2006 The University of Tennessee and The University
+ * Copyright (c) 2004-2008 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
  * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
@@ -102,7 +102,7 @@ int opal_free_list_grow(opal_free_list_t* flist, size_t num_elements)
     opal_list_append(&(flist->fl_allocations), (opal_list_item_t*) alloc_ptr);
     ptr = alloc_ptr + sizeof(opal_list_item_t);
 
-    mod = (intptr_t)ptr % CACHE_LINE_SIZE;
+    mod = (uintptr_t)ptr % CACHE_LINE_SIZE;
     if(mod != 0) {
         ptr += (CACHE_LINE_SIZE - mod);
     }