slub: Avoid warning for !CONFIG_SLUB_DEBUG

Move the #ifdef so that get_map is only defined if CONFIG_SLUB_DEBUG is defined.

Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
diff --git a/mm/slub.c b/mm/slub.c
index 461199f..8657ab8 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -326,6 +326,7 @@
 	return x.x & OO_MASK;
 }
 
+#ifdef CONFIG_SLUB_DEBUG
 /*
  * Determine a map of object in use on a page.
  *
@@ -341,7 +342,6 @@
 		set_bit(slab_index(p, s, addr), map);
 }
 
-#ifdef CONFIG_SLUB_DEBUG
 /*
  * Debug settings:
  */