anv: Handle null in all destructors

This fixes a bunch of new CTS tests which look for exactly this.  Even in
the cases where we just call vk_free to free a CPU data structure, we still
handle NULL explicitly.  This way we're less likely to forget to handle
NULL later should we actually do something less trivial.

Cc: "13.0" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/intel/vulkan/anv_pipeline.c

@@ -75,6 +75,9 @@ void anv_DestroyShaderModule(
    ANV_FROM_HANDLE(anv_device, device, _device);
    ANV_FROM_HANDLE(anv_shader_module, module, _module);
 
+   if (!module)
+      return;
+
    vk_free2(&device->alloc, pAllocator, module);
 }
 
@@ -189,6 +192,9 @@ void anv_DestroyPipeline(
    ANV_FROM_HANDLE(anv_device, device, _device);
    ANV_FROM_HANDLE(anv_pipeline, pipeline, _pipeline);
 
+   if (!pipeline)
+      return;
+
    anv_reloc_list_finish(&pipeline->batch_relocs,
                          pAllocator ? pAllocator : &device->alloc);
    if (pipeline->blend_state.map)