utils: fix in/pipe utilities

These examples stopped building with 3b36d17cf.

Fixes: 3b36d17cf18bd9ad13f043256371222e2845e4d9
Change-Id: I14218769afd1e9b8171de33b88028ef4a052ce17
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/utils/mctp-pipe.c b/utils/mctp-pipe.c
index 45ff886..3c4c316 100644
--- a/utils/mctp-pipe.c
+++ b/utils/mctp-pipe.c
@@ -43,8 +43,8 @@
 	mctp_serial_open_fd(serial[0], mctp_fds[0]);
 	mctp_serial_open_fd(serial[1], mctp_fds[1]);
 
-	mctp_serial_register_bus(serial[0], mctp[0], eids[0]);
-	mctp_serial_register_bus(serial[1], mctp[1], eids[1]);
+	mctp_register_bus(mctp[0], mctp_binding_serial_core(serial[0]), eids[0]);
+	mctp_register_bus(mctp[1], mctp_binding_serial_core(serial[1]), eids[1]);
 
 	mctp_set_rx_all(mctp[1], rx_message, NULL);