mboxd: Rename mboxd_msg to transport_mbox

Change-Id: I0f4e206648c02a98fa938a7e582470c8d90904f1
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/test/mbox.h b/test/mbox.h
index 4344622..30d36b6 100644
--- a/test/mbox.h
+++ b/test/mbox.h
@@ -9,7 +9,7 @@
 
 #include "common.h"
 #include "mbox.h"
-#include "mboxd_msg.h"
+#include "transport_mbox.h"
 
 #include "tmpf.h"