net: core: Free packet properly if TTL/hop limit is 0

We drop the packet if TTL or hop limit is 0, but we should
also unref the packet in this case because we return 0 to
the caller which is not then able to free the packet because
it thinks that the packet was sent properly.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>

Author: jukkar

subsys/net/ip/net_core.c

@@ -393,6 +393,7 @@ int net_try_send_data(struct net_pkt *pkt, k_timeout_t timeout)
 		 * we just silently drop the packet by returning 0.
 		 */
 		if (status == -ENOMSG) {
+			net_pkt_unref(pkt);
 			ret = 0;
 			goto err;
 		}