selinux: sparse fix: fix warnings in netlink code

Fix sparse warnings in SELinux Netlink code.

Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/netlink.c b/security/selinux/netlink.c
index 36ac257..ce3f481 100644
--- a/security/selinux/netlink.c
+++ b/security/selinux/netlink.c
@@ -19,6 +19,8 @@
 #include <linux/selinux_netlink.h>
 #include <net/net_namespace.h>
 
+#include "security.h"
+
 static struct sock *selnl;
 
 static int selnl_msglen(int msgtype)