session: improve use of session handles

First step towards moving to an 8 byte struct instead of u64.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Idd0b95520ab7158e175b9af1702fc09c0613a4bb
diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 41a11b7..b89052f 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -159,8 +159,8 @@
   svm_fifo_t *ct_tx_fifo;
   vcl_session_msg_t *accept_evts_fifo;
 
-  u64 vpp_handle;
-  u64 parent_handle;
+  session_handle_t vpp_handle;
+  session_handle_t parent_handle;
   u32 listener_index;		/**< index of parent listener (if any) */
   int n_accepted_sessions;	/**< sessions accepted by this listener */
   vppcom_epoll_t vep;