update incremental test -- returning that reference was illegal

Also, changing the pattern in the closure in this way doesn't affect
the closure *creator* in particular.

Author: nikomatsakis

src/test/incremental/hashes/closure_expressions.rs

@@ -60,14 +60,14 @@ pub fn add_parameter() {
 // Change parameter pattern ----------------------------------------------------
 #[cfg(cfail1)]
 pub fn change_parameter_pattern() {
-    let _ = |x: &u32| x;
+    let _ = |x: &u32| { println!("{}", x); };
 }
 
 #[cfg(not(cfail1))]
-#[rustc_clean(cfg="cfail2", except="HirBody, MirValidated, TypeckTables")]
+#[rustc_clean(cfg="cfail2", except="HirBody, TypeckTables")]
 #[rustc_clean(cfg="cfail3")]
 pub fn change_parameter_pattern() {
-    let _ = |&x: &u32| x;
+    let _ = |&x: &u32| { println!("{}", x); };
 }