Add clippy suggestions (#6203)

* add clippy suggestions

* revert &/ref change

* Update cranelift/isle/isle/src/parser.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

---------

Co-authored-by: Jamey Sharp <jamey@minilop.net>

cranelift/control/src/zero_sized.rs

@@ -13,7 +13,7 @@ pub struct ControlPlane {
 /// disabled. It doesn't consume any bytes and always returns a default
 /// control plane.
 impl arbitrary::Arbitrary<'_> for ControlPlane {
-    fn arbitrary<'a>(_u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
+    fn arbitrary(_u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Self> {
         Ok(Self::default())
     }
 }