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>

lib/string.c

diff --git a/lib/string.c b/lib/string.c
index dc4a863..26df13e 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -22,7 +22,10 @@
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
-#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
 
 #ifndef __HAVE_ARCH_STRNICMP
 /**