batman-adv: Prefix soft-interface non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index bceb3d7..8226b1c 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -51,7 +51,7 @@
 	}
 
 	/* push to the ethernet header. */
-	if (my_skb_head_push(skb, ETH_HLEN) < 0)
+	if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
 		goto send_skb_err;
 
 	skb_reset_mac_header(skb);