[PATCH 0/1] MR2892: wined3d: Fix uninitialized variable warning.

[Davide Beatrici (＠davidebeatrici)]

```c
dlls/wined3d/context_vk.c:2377:42: warning: ‘null_binding’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 2377 |                     *null_buffer_binding = b->binding = null_binding;
      |                     ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
```