vk/private.h: Handle a NULL bo but valid offset in __gen_combine_address

src/vulkan/anv_private.h

@@ -505,7 +505,7 @@ __gen_combine_address(struct anv_batch *batch, void *location,
                       const struct anv_address address, uint32_t delta)
 {
    if (address.bo == NULL) {
-      return delta;
+      return address.offset + delta;
    } else {
       assert(batch->start <= location && location < batch->end);