Rollup merge of rust-lang#163905 - Jules-Bertholet:bootstrap-tweak, r=Kobzol

Remove redundant closure in bootstrap

My PR rust-lang#163717 would make Clippy start linting `redundant_closure_for_method_calls` here; let's get ahead of that.

@rustbot label T-bootstrap
@rustbot ready

r? bootstrap

Author: JonathanBrouwer

src/bootstrap/src/core/builder/mod.rs

@@ -1120,10 +1120,9 @@ impl<'a> Builder<'a> {
             Subcommand::Run { .. } => (Kind::Run, &paths[..]),
             Subcommand::Clean { .. } => (Kind::Clean, &paths[..]),
             Subcommand::Format { .. } => (Kind::Format, &[][..]),
-            Subcommand::Setup { profile: ref path } => (
-                Kind::Setup,
-                path.as_ref().map_or([].as_slice(), |path| std::slice::from_ref(path)),
-            ),
+            Subcommand::Setup { profile: ref path } => {
+                (Kind::Setup, path.as_ref().map_or([].as_slice(), std::slice::from_ref))
+            }
             Subcommand::Vendor { .. } => (Kind::Vendor, &paths[..]),
             Subcommand::Perf { .. } => (Kind::Perf, &paths[..]),
         };