VPE_API small fix for LISP locator_set

- add documentation
- use new feature in vpe_api

Change-Id: I2708383aa886494d948feea1869c3fabae94c7bf
Signed-off-by: Andrej Kozemcak <akozemca@cisco.com>
diff --git a/vpp/vpp-api/vpe.api b/vpp/vpp-api/vpe.api
index 6aa2213..0783949 100644
--- a/vpp/vpp-api/vpe.api
+++ b/vpp/vpp-api/vpe.api
@@ -2157,6 +2157,8 @@
     @param context - sender context, to match reply w/ request
     @param is_add - add address if non-zero, else delete
     @param locator_set_name - locator name
+    @param locator_num - number of locators
+    @param locators - Lisp locator data
 */
 define lisp_add_del_locator_set {
     u32 client_index;
@@ -2164,7 +2166,7 @@
     u8  is_add;
     u8  locator_set_name[64];
     u32 locator_num;
-    u8  locators[0];
+    u8  locators[locator_num];
 };
 
 /** \brief Reply for locator_set add/del