Examples: Vulkan: Fix for empty draw data (init time) + fixed warning.

examples/vulkan_example/imgui_impl_glfw_vulkan.cpp

@@ -170,6 +170,8 @@ void ImGui_ImplGlfwVulkan_RenderDrawData(ImDrawData* draw_data)
 {
     VkResult err;
     ImGuiIO& io = ImGui::GetIO();
+    if (draw_data->TotalVtxCount == 0)
+        return;
 
     // Create the Vertex Buffer:
     size_t vertex_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);

examples/vulkan_example/main.cpp

@@ -507,7 +507,7 @@ static void cleanup_vulkan()
 static void frame_begin()
 {
     VkResult err;
-    while (true)
+    for (;;)
     {
         err = vkWaitForFences(g_Device, 1, &g_Fence[g_FrameIndex], VK_TRUE, 100);
         if (err == VK_SUCCESS) break;