tests: Wait idle instead of ignoring errors

Prior to destroying objects wait for cmd buffer to complete to avoid errors rather than
ignoring the errors.
diff --git a/tests/layer_validation_tests.cpp b/tests/layer_validation_tests.cpp
index ec659ec..9bc69df 100644
--- a/tests/layer_validation_tests.cpp
+++ b/tests/layer_validation_tests.cpp
@@ -14100,7 +14100,7 @@
     vkDestroyFence(m_device->device(), fence, nullptr);
     m_errorMonitor->VerifyFound();
 
-    m_errorMonitor->SetDesiredFailureMsg(0, "");
+    vkQueueWaitIdle(m_device->m_queue);
     vkDestroySemaphore(m_device->device(), semaphore, nullptr);
     vkDestroyFence(m_device->device(), fence, nullptr);
     vkDestroyEvent(m_device->device(), event, nullptr);