batman-adv: Use packing of 2 for all headers before an ethernet header

	uint8_t  rr[BATADV_RR_LEN][ETH_ALEN];

};

/* All packet headers in front of an ethernet header have to be completely

 * divisible by 2 but not by 4 to make the payload after the ethernet

 * header again 4 bytes boundary aligned.

 *

 * A packing of 2 is necessary to avoid extra padding at the end of the struct

 * caused by a structure member which is larger than two bytes. Otherwise

 * the structure would not fulfill the previously mentioned rule to avoid the

 * misalignment of the payload after the ethernet header. It may also lead to

 * leakage of information when the padding it not initialized before sending.

 */

#pragma pack(2)

struct batadv_unicast_packet {

	struct batadv_header header;

	uint8_t  ttvn; /* destination translation table version number */

	/* "4 bytes boundary + 2 bytes" long to make the payload after the

	 * following ethernet header again 4 bytes boundary aligned

	 */

} __packed;

};

#pragma pack()

struct batadv_vis_packet {

	struct batadv_header header;