SLUB: Fix *86ism: cache_line_size is not defined on all arches.

Define cache_line_size if it is not provided by the arch.

This should be done more elegantly someday.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.21-mm1/mm/slub.c
===================================================================
--- linux-2.6.21-mm1.orig/mm/slub.c	2007-05-07 16:04:28.000000000 -0700
+++ linux-2.6.21-mm1/mm/slub.c	2007-05-07 16:05:02.000000000 -0700
@@ -1709,6 +1709,11 @@ static inline int calculate_order(int si
 	return -ENOSYS;
 }
 
+/* Not all arches define cache_line_size */
+#ifndef cache_line_size
+#define cache_line_size()	L1_CACHE_BYTES
+#endif
+
 /*
  * Figure out what the alignment of the objects will be.
  */