session: add wrk context

Change-Id: I66ca0ddea872948507d078e405eb90f9f3a0e897
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/session-apps/echo_server.c b/src/vnet/session-apps/echo_server.c
index 3ee33ea..7771075 100644
--- a/src/vnet/session-apps/echo_server.c
+++ b/src/vnet/session-apps/echo_server.c
@@ -389,7 +389,7 @@
   vec_validate (esm->rx_retries, num_threads - 1);
   for (i = 0; i < vec_len (esm->rx_retries); i++)
     vec_validate (esm->rx_retries[i],
-		  pool_elts (session_manager_main.sessions[i]));
+		  pool_elts (session_manager_main.wrk[i].sessions));
   esm->rcv_buffer_size = clib_max (esm->rcv_buffer_size, esm->fifo_size);
   for (i = 0; i < num_threads; i++)
     vec_validate (esm->rx_buf[i], esm->rcv_buffer_size);