nrf_rpc: fix initialization corner case

When initializing multiple groups that share the same
transport, it may happen that a device receives an init
packet for a group whose internal members have not been
initialized yet, leading to the bus fault.

Make sure that internal members of all groups have been
initialized before ANY transport is started to prevent
that.

Signed-off-by: Damian Krolik <[email protected]>

Author: Damian-Nordic

nrf_rpc/nrf_rpc.c

@@ -438,6 +438,13 @@ static int transport_init(nrf_rpc_tr_receive_handler_t receive_cb)
 			}
 		}
 
+	}
+
+	for (NRF_RPC_AUTO_ARR_FOR(iter, group, &nrf_rpc_groups_array,
+				 const struct nrf_rpc_group)) {
+		const struct nrf_rpc_tr *transport = group->transport;
+		struct nrf_rpc_group_data *data = group->data;
+
 		err = transport->api->init(transport, receive_cb, NULL);
 		if (err) {
 			NRF_RPC_ERR("Failed to initialize transport, err: %d", err);