libmemif: ubuntu 18.04 build fix

Change-Id: I6624cacd625eea6a9b8214f67d14ec162e2c0195
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
diff --git a/extras/libmemif/src/libmemif.h b/extras/libmemif/src/libmemif.h
index f5df79c..a14a102 100644
--- a/extras/libmemif/src/libmemif.h
+++ b/extras/libmemif/src/libmemif.h
@@ -169,7 +169,7 @@
 
   memif_interface_id_t interface_id;
   uint8_t interface_name[32];
-  uint8_t instance_name[32];
+  uint8_t instance_name[32];	/*!< deprecated, will be removed in 2.0 */
   memif_interface_mode_t mode:8;
 } memif_conn_args_t;
 
@@ -308,7 +308,7 @@
 
 /** \brief Memif initialization
     @param on_control_fd_update - if control fd updates inform user to watch new fd
-    @param app_name - application name
+    @param app_name - application name (will be truncated to 32 chars)
 
     if param on_control_fd_update is set to NULL,
     libmemif will handle file descriptor event polling