winevulkan: Initialize Vulkan in native_vkGetInstanceProcAddrWINE.

In the past this was done in DllMain, the removal broke winelib applications.

Signed-off-by: Georg Lehmann <dadschoorse@gmail.com>
Signed-off-by: Liam Middlebrook <lmiddlebrook@nvidia.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/winevulkan/vulkan.c

@@ -2053,6 +2053,10 @@ static void *wine_vk_get_global_proc_addr(const char *name)
  */
 void *native_vkGetInstanceProcAddrWINE(VkInstance instance, const char *name)
 {
+    wine_vk_init_once();
+    if (!vk_funcs)
+        return NULL;
+
     return vk_funcs->p_vkGetInstanceProcAddr(instance, name);
 }