Improve api trace replay consistency checking

Change-Id: I2c4b9646d53e4c008ccbe6d09c6a683c776c1f60
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vlibapi/api.h b/src/vlibapi/api.h
index b40ece1..2cbeb63 100644
--- a/src/vlibapi/api.h
+++ b/src/vlibapi/api.h
@@ -189,6 +189,9 @@
 
   char *region_name;
   char *root_path;
+
+  /* Replay in progress? */
+  int replay_in_progress;
 } api_main_t;
 
 extern api_main_t api_main;