batman-adv: Remove unused skb_reset_mac_header()

During broadcast queueing, the skb_reset_mac_header() sets the skb
to a place invalid for a MAC header, pointing right into the
batman-adv broadcast packet. Luckily, no one seems to actually use
eth_hdr(skb) afterwards until batadv_send_skb_packet() resets the
header to a valid position again.

Therefore removing this unnecessary, weird skb_reset_mac_header()
call.
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net/batman-adv/send.c

@@ -586,8 +586,6 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 	bcast_packet->ttl--;
 
-	skb_reset_mac_header(newskb);
-
 	forw_packet->skb = newskb;
 
 	INIT_DELAYED_WORK(&forw_packet->delayed_work,