`bool_assert_comparison` improve the suggestion to include the expression

[xFrednet]

The lint message for the bool_assert_comparison lint currently look like this:

warning: used `assert_eq!` with a literal bool
 --> src/main.rs:5:5
  |
5 |     assert_eq!(some_bool_expression, false);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `assert!(..)`

I think the suggestion can be improved to include the actual expression that should be put in the assert! instead of just having the placeholder ...

The text for the suggestion can be retrieved with functions from clippy_utils::source.

[phansch]

@rustbot claim

[ABouttefeux]

@rustbot claim