docs(tvix/store): correct some cargo doc warnings

Change-Id: I5053e3f7dcea01e75baa933e4986396583ff22e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8831
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>

tvix/store/src/nar/renderer.rs

@@ -14,7 +14,7 @@ use std::{
 };
 use tracing::warn;
 
-/// Invoke [render_nar], and return the size and sha256 digest of the produced
+/// Invoke [write_nar], and return the size and sha256 digest of the produced
 /// NAR output.
 pub fn calculate_size_and_sha256(
     root_node: &proto::node::Node,