api: refactor api data storage

single struct to hold all api handler, flags, etc.
Provide functions to toggle flags instead of writing directly to
internal data.

Type: refactor
Change-Id: I4730d7290e57489de8eda34a72211527e015b721
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vlibapi/api_helper_macros.h b/src/vlibapi/api_helper_macros.h
index 6b5b37a..9c93d33 100644
--- a/src/vlibapi/api_helper_macros.h
+++ b/src/vlibapi/api_helper_macros.h
@@ -30,7 +30,7 @@
 #define _NATIVE_TO_NETWORK(t, rmp)                                            \
   api_main_t *am = vlibapi_get_main ();                                       \
   void (*endian_fp) (void *);                                                 \
-  endian_fp = am->msg_endian_handlers[t + (REPLY_MSG_ID_BASE)];               \
+  endian_fp = am->msg_data[t + (REPLY_MSG_ID_BASE)].endian_handler;           \
   (*endian_fp) (rmp);
 
 #define REPLY_MACRO(msg)                                                      \