Deny clippy::format_in_format_args and fix the only occurrence

Author: joshtriplett

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -2460,16 +2460,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             spans.push_span_label(
                                 param.span,
                                 format!(
-                                    "{} {} to match the {} type of this parameter",
+                                    "{} need{} to match the {} type of this parameter",
                                     display_list_with_comma_and(&other_param_matched_names),
-                                    format!(
-                                        "need{}",
-                                        pluralize!(if other_param_matched_names.len() == 1 {
-                                            0
-                                        } else {
-                                            1
-                                        })
-                                    ),
+                                    pluralize!(if other_param_matched_names.len() == 1 {
+                                        0
+                                    } else {
+                                        1
+                                    }),
                                     matched_ty,
                                 ),
                             );

src/bootstrap/src/core/build_steps/clippy.rs

@@ -391,7 +391,11 @@ impl Step for CI {
         let compiler_clippy_cfg = LintConfig {
             allow: vec!["clippy::all".into()],
             warn: vec![],
-            deny: vec!["clippy::correctness".into(), "clippy::clone_on_ref_ptr".into()],
+            deny: vec![
+                "clippy::correctness".into(),
+                "clippy::clone_on_ref_ptr".into(),
+                "clippy::format_in_format_args".into(),
+            ],
             forbid: vec![],
         };