Silence unhandled structure warning

Change-Id: I1260f6a6cae694f4c2336bee6e9baa0db93ae527
diff --git a/src/vulkan/wsi/wsi_common.c b/src/vulkan/wsi/wsi_common.c
index 3ce4db1..a4441b7 100644
--- a/src/vulkan/wsi/wsi_common.c
+++ b/src/vulkan/wsi/wsi_common.c
@@ -58,11 +58,17 @@
    WSI_GET_CB(GetPhysicalDeviceQueueFamilyProperties);
 #undef WSI_GET_CB
 
+#ifdef WSI_USE_DRM
    wsi->pci_bus_info.sType =
       VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PCI_BUS_INFO_PROPERTIES_EXT;
+#endif
    VkPhysicalDeviceProperties2 pdp2 = {
       .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2,
+#ifdef WSI_USE_DRM
       .pNext = &wsi->pci_bus_info,
+#else
+      .pNext = NULL,
+#endif
    };
    GetPhysicalDeviceProperties2(pdevice, &pdp2);