ovn-controller-vtep: Call binding_cleanup() before gateway_cleanup().

Otherwise, binding_cleanup() will be a no-op since all related chassis
entries are deleted in gateway_cleanup().

Found by inspection.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Russell Bryant <rbryant@redhat.com>

ovn/controller-vtep/ovn-controller-vtep.c

@@ -124,8 +124,8 @@ main(int argc, char *argv[])
 
         /* Run all of the cleanup functions, even if one of them returns false.
          * We're done if all of them return true. */
-        done = gateway_cleanup(&ctx);
-        done = binding_cleanup(&ctx) && done;
+        done = binding_cleanup(&ctx);
+        done = gateway_cleanup(&ctx) && done;
         if (done) {
             poll_immediate_wake();
         }