Clippy suggests the same boolean expression as the code

[betseg]

Context: I have a piece of code to check if a matrix is a unit matrix:

if i != j && self[[i, j]] != 0 || i == j && self[[i, j]] != 1 {

and Clippy thinks it's not minimal and suggest the same code:

warning: this boolean expression can be simplified
  --> src/lib.rs:73:20
   |
73 |                 if i != j && self[[i, j]] != 0 || i == j && self[[i, j]] != 1 {
   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `i != j && self[[i, j]] != 0 || i == j && self[[i, j]] != 1`
   |
   = note: #[warn(clippy::nonminimal_bool)] on by default
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool

---

Version info:

$ cargo clippy -V
clippy 0.0.212 (e3cb40e 2019-06-25)

I'm looking at this. The reason for the error is that we change i == j to NOT(i != j) when translating to QMM and then think we've found a simplification when we change it back while generating suggestions.

This is probably the same error as #3847