Read error before setting error pointer to null

I'm in a rush to get the tag out today and I'm making a mess. The
previous patch set an error pointer to null in apfs_node_split(), but I
didn't notice that the actual error would get read later. Reorder this.
I usually would just squash this into the previous patch, but in my rush
I have already pushed it.

Signed-off-by: Ernesto A. Fernández <[email protected]>

node.c

@@ -1266,9 +1266,9 @@ int apfs_node_split(struct apfs_query *query)
 
 	new_node = apfs_create_node(sb, storage);
 	if (IS_ERR(new_node)) {
-		new_node = NULL;
 		apfs_err(sb, "node creation failed");
 		err = PTR_ERR(new_node);
+		new_node = NULL;
 		goto out;
 	}
 	new_node->tree_type = old_node->tree_type;