message: Remove needless borrow
diff: @@ -797,14 +797,14 @@ fn emit_warnings_of_unused_patches(
  {
  use std::fmt::Write;
  let mut msg = String::new();
  - writeln!(&mut msg, "Patch `{}` {}", unused, MESSAGE)?;
  + writeln!(msg, "Patch `{}` {}", unused, MESSAGE)?;
  write!(
  - &mut msg,
  + msg,
  "Perhaps you misspell the source URL being patched.\n\
  Possible URLs for `[patch.<URL>]`:",
  )?;
  for id in ids.iter() {
  - write!(&mut msg, "\n {}", id.display_registry_name())?;
  + write!(msg, "\n {}", id.display_registry_name())?;
  }
  ws.config().shell().warn(msg)?;
  }
  