[gnome-remote-desktop] tests/rdp: Add missing NULL check on stop_event

[Jonas Ådahl <jadahl src gnome org>]

commit 570fd69ea03ff41030cc75d80216a7dfa131c50a
Author: Pascal Nowack <Pascal Nowack gmx de>
Date:   Fri May 6 15:51:17 2022 +0200

    tests/rdp: Add missing NULL check on stop_event
    
    It must be non-NULL for a successful test run.

 tests/test-client-rdp.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/tests/test-client-rdp.c b/tests/test-client-rdp.c
index 8c9c9602..91f88489 100644
--- a/tests/test-client-rdp.c
+++ b/tests/test-client-rdp.c
@@ -300,6 +300,8 @@ rdp_client_new (freerdp    *instance,
   PubSub_SubscribeTerminate (rdp_context->pubSub, on_terminate);
 
   rdp_peer_context->stop_event = CreateEvent (NULL, TRUE, FALSE, NULL);
+  if (!rdp_peer_context->stop_event)
+    return FALSE;
 
   return TRUE;
 }