lib: reduce the use of module.h wherever possible

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/lib/average.c b/lib/average.c
index 5576c28..99a67e6 100644
--- a/lib/average.c
+++ b/lib/average.c
@@ -5,8 +5,9 @@
  * Version 2.  See the file COPYING for more details.
  */
 
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/average.h>
+#include <linux/kernel.h>
 #include <linux/bug.h>
 #include <linux/log2.h>