Use old error when there's partial resolution

The new error was confusing when there was partial resolution (something
like `std::io::nonexistent`); the old one is better for those cases.

Author: camelid

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -1575,11 +1575,16 @@ fn resolution_failure(
                         _ => None,
                     };
                     // See if this was a module: `[path]` or `[std::io::nope]`
-                    if let Some(_module) = last_found_module {
-                        let note = format!(
-                            "there is no item named `{}` in scope",
-                            unresolved
-                        );
+                    if let Some(module) = last_found_module {
+                        let note = if partial_res.is_some() {
+                            let module_name = collector.cx.tcx.item_name(module);
+                            format!(
+                                "the module `{}` contains no item named `{}`",
+                                module_name, unresolved
+                            )
+                        } else {
+                            format!("there is no item named `{}` in scope", unresolved)
+                        };
                         if let Some(span) = sp {
                             diag.span_label(span, &note);
                         } else {

src/test/rustdoc-ui/intra-link-errors.rs

@@ -18,11 +18,11 @@
 
 /// [std::io::not::here]
 //~^ ERROR unresolved link
-//~| NOTE there is no item named `not` in scope
+//~| NOTE `io` contains no item named `not`
 
 /// [type@std::io::not::here]
 //~^ ERROR unresolved link
-//~| NOTE there is no item named `not` in scope
+//~| NOTE `io` contains no item named `not`
 
 /// [std::io::Error::x]
 //~^ ERROR unresolved link

src/test/rustdoc-ui/intra-link-errors.stderr

@@ -26,13 +26,13 @@ error: unresolved link to `std::io::not::here`
   --> $DIR/intra-link-errors.rs:19:6
    |
 LL | /// [std::io::not::here]
-   |      ^^^^^^^^^^^^^^^^^^ there is no item named `not` in scope
+   |      ^^^^^^^^^^^^^^^^^^ the module `io` contains no item named `not`
 
 error: unresolved link to `std::io::not::here`
   --> $DIR/intra-link-errors.rs:23:6
    |
 LL | /// [type@std::io::not::here]
-   |      ^^^^^^^^^^^^^^^^^^^^^^^ there is no item named `not` in scope
+   |      ^^^^^^^^^^^^^^^^^^^^^^^ the module `io` contains no item named `not`
 
 error: unresolved link to `std::io::Error::x`
   --> $DIR/intra-link-errors.rs:27:6