netfilter: add include guard to nf_conntrack_h323_types.h

Add a header include guard just in case.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter/nf_conntrack_h323_types.h

@@ -4,6 +4,9 @@
  * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
  */
 
+#ifndef _NF_CONNTRACK_H323_TYPES_H
+#define _NF_CONNTRACK_H323_TYPES_H
+
 typedef struct TransportAddress_ipAddress {	/* SEQUENCE */
 	int options;		/* No use */
 	unsigned int ip;
@@ -931,3 +934,5 @@ typedef struct RasMessage {	/* CHOICE */
 		InfoRequestResponse infoRequestResponse;
 	};
 } RasMessage;
+
+#endif /* _NF_CONNTRACK_H323_TYPES_H */