Typos.  A bunch of typos I've been collecting.

Change-Id: I53ab8d17914e6563110354e4052109ac02bf8f3b
Signed-off-by: Paul Vinciguerra <pvinci@vinciconsulting.com>
diff --git a/src/vnet/session-apps/echo_server.c b/src/vnet/session-apps/echo_server.c
index 941c16d..ab90004 100644
--- a/src/vnet/session-apps/echo_server.c
+++ b/src/vnet/session-apps/echo_server.c
@@ -29,7 +29,7 @@
 
   u32 app_index;		/**< Server app index */
   u32 my_client_index;		/**< API client handle */
-  u32 node_index;		/**< process node index for evnt scheduling */
+  u32 node_index;		/**< process node index for event scheduling */
 
   /*
    * Config params