fix some manual_map

Author: matthiaskrgr

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -959,13 +959,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                         None
                     }
                 }
-                hir::ExprKind::MethodCall(_, _, args, span) => {
-                    if let Some(def_id) = typeck_results.type_dependent_def_id(*hir_id) {
-                        Some((def_id, *span, *args))
-                    } else {
-                        None
-                    }
-                }
+                hir::ExprKind::MethodCall(_, _, args, span) => typeck_results
+                    .type_dependent_def_id(*hir_id)
+                    .map(|def_id| (def_id, *span, *args)),
                 _ => None,
             }
         };

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -537,7 +537,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     && binding_id != self.binding_id
                 {
                     if self.check_and_add_sugg_binding(LetStmt {
-                        ty_hir_id_opt: if let Some(ty) = ty { Some(ty.hir_id) } else { None },
+                        ty_hir_id_opt: ty.map(|ty| ty.hir_id),
                         binding_id,
                         span: pat.span,
                         init_hir_id: init.hir_id,