Bluetooth: Mesh: Fix SDU length check

The code was passing the wrong first parameter to the sdu_len_is_ok()
function.

Fixes #3985
Fixes #3984

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

subsys/bluetooth/host/mesh/transport.c

@@ -980,7 +980,7 @@ static int trans_seg(struct net_buf_simple *buf, struct bt_mesh_net_rx *net_rx)
 	}
 
 	/* Bail out early if we're not ready to receive such a large SDU */
-	if (!sdu_len_is_ok(&net_rx->ctx, seg_n)) {
+	if (!sdu_len_is_ok(net_rx->ctl, seg_n)) {
 		BT_ERR("Too big incoming SDU length");
 		send_ack(net_rx->sub, net_rx->dst, net_rx->ctx.addr,
 			 net_rx->ctx.send_ttl, seq_zero, 0);