batman-adv: fix header alignment by unrolling batadv_header

The size of the batadv_header of 3 is problematic on some architectures
which automatically pad all structures to a 32 bit boundary. To not lose
performance by packing this struct, better embed it into the various
host structures.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index c83be5e..fba4dcf 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -161,11 +161,11 @@
 		return false;
 
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
-	unicast_packet->header.version = BATADV_COMPAT_VERSION;
+	unicast_packet->version = BATADV_COMPAT_VERSION;
 	/* batman packet type: unicast */
-	unicast_packet->header.packet_type = BATADV_UNICAST;
+	unicast_packet->packet_type = BATADV_UNICAST;
 	/* set unicast ttl */
-	unicast_packet->header.ttl = BATADV_TTL;
+	unicast_packet->ttl = BATADV_TTL;
 	/* copy the destination for faster routing */
 	memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
 	/* set the destination tt version number */
@@ -221,7 +221,7 @@
 		goto out;
 
 	uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
-	uc_4addr_packet->u.header.packet_type = BATADV_UNICAST_4ADDR;
+	uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
 	memcpy(uc_4addr_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
 	uc_4addr_packet->subtype = packet_subtype;
 	uc_4addr_packet->reserved = 0;
@@ -436,7 +436,7 @@
 
 	/* as we have a copy now, it is safe to decrease the TTL */
 	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
-	bcast_packet->header.ttl--;
+	bcast_packet->ttl--;
 
 	skb_reset_mac_header(newskb);