loader: Fix createInstance to pass pAllocator down

Also fix bug where createDevice failure removes logical device from icd
struct
diff --git a/loader/trampoline.c b/loader/trampoline.c
index 6468ce8..9cca6aa 100644
--- a/loader/trampoline.c
+++ b/loader/trampoline.c
@@ -181,7 +181,7 @@
     }
 
     created_instance = (VkInstance) ptr_instance;
-    res = loader_create_instance_chain(pCreateInfo, NULL, ptr_instance, created_instance);
+    res = loader_create_instance_chain(pCreateInfo, pAllocator, ptr_instance, created_instance);
 
     if (res == VK_SUCCESS) {
         wsi_create_instance(ptr_instance, pCreateInfo);