BE: clippy clean

Summary:
We are getting some clippy warnings about [complex types](https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity), related to eqwalizer queries on salsa, e.g.

```
Result<Arc<BTreeMap<ModuleName, BTreeMap<Id, Arc<TypeDecl>>>>, Error>;
```

We believe this type is clear enough, so raise the threshold of the clippy lint to allow it.

Also fix one other clippy warning about unreachable code.

Reviewed By: ilya-klyuchnikov

Differential Revision: D74248916

fbshipit-source-id: 7e9e603729ce480a6c193f9cba6129ee637be880

clippy.toml

@@ -0,0 +1,9 @@
+# Clippy parameter settings
+
+# See https://doc.rust-lang.org/clippy/lint_configuration.html for possible settings
+
+
+# Default is 250
+# see https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
+type-complexity-threshold = 350
+

crates/ide/src/diagnostics/nonstandard_integer_formatting.rs

@@ -96,7 +96,6 @@ fn check_function(
                                 &formatted_src_text,
                             ) {
                                 diagnostics.push(diagnostic);
-                                Some(());
                             }
                         }
                     }