Misleading note for error message in proc-macro

[antoyo]

Hi.
I created a repository that makes Rust show the following error message:

error[E0308]: mismatched types
 --> src/main.rs:7:1
  |
7 | #[my_attr]
  | ^^^^^^^^^^
  | |
  | expected &str, found struct `std::string::String`
  | help: consider borrowing here: `&#[my_attr]`
  |
  = note: expected type `&str`
             found type `std::string::String`

The help note is misleading and, obviously, does not work.
Thanks to fix this.

[estebank]

Duplicate of #48364, needs to change the following to not include the suggestion when dealing with a macro call:

rust/src/librustc_typeck/check/demand.rs

Line 259 in 9fd7da9

let sp = self.sess().codemap().call_span_if_macro(expr.span);

[estebank]

Should have been fixed when #48364 was fixed.