mm: Map most files to use export.h instead of module.h

The files changed within are only using the EXPORT_SYMBOL
macro variants.  They are not using core modular infrastructure
and hence don't need module.h but only the export.h header.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/mm/mempool.c b/mm/mempool.c
index 1a3bc3d..e73641b 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -10,7 +10,7 @@
 
 #include <linux/mm.h>
 #include <linux/slab.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/mempool.h>
 #include <linux/blkdev.h>
 #include <linux/writeback.h>