batman-adv: Fix broadcast/ogm queue limit on a removed interface

commit c4fdb6cf upstream.

When removing a single interface while a broadcast or ogm packet is
still pending then we will free the forward packet without releasing the
queue slots again.

This patch is supposed to fix this issue.

Fixes: 6d5808d4 ("batman-adv: Add missing hardif_free_ref in forw_packet_free")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
[sven@narfation.org: fix conflicts with current version]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/batman-adv/send.c

@@ -375,6 +375,9 @@ void purge_outstanding_packets(struct bat_priv *bat_priv,
 
 		if (pending) {
 			hlist_del(&forw_packet->list);
+			if (!forw_packet->own)
+				atomic_inc(&bat_priv->bcast_queue_left);
+
 			forw_packet_free(forw_packet);
 		}
 	}
@@ -404,6 +407,9 @@ void purge_outstanding_packets(struct bat_priv *bat_priv,
 
 		if (pending) {
 			hlist_del(&forw_packet->list);
+			if (!forw_packet->own)
+				atomic_inc(&bat_priv->batman_queue_left);
+
 			forw_packet_free(forw_packet);
 		}
 	}