selinux: Add export.h to files using EXPORT_SYMBOL/THIS_MODULE

The pervasive, but implicit presence of <linux/module.h> meant
that things like this file would happily compile as-is.  But
with the desire to phase out the module.h being included everywhere,
point this file at export.h which will give it THIS_MODULE and
the EXPORT_SYMBOL variants.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e545b9f..1126c10 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -80,6 +80,7 @@
 #include <linux/posix-timers.h>
 #include <linux/syslog.h>
 #include <linux/user_namespace.h>
+#include <linux/export.h>
 
 #include "avc.h"
 #include "objsec.h"