Dodge 'use' keyword in testsuite. Was burning tree.

src/test/compile-fail/kindck-implicit-close-over-mut-var.rs

@@ -1,10 +1,10 @@
-fn use(_i: int) {}
+fn user(_i: int) {}
 
 fn foo() {
     // Here, i is *moved* into the closure: Not actually OK
     let mut i = 0;
     do task::spawn {
-        use(i); //~ ERROR mutable variables cannot be implicitly captured
+        user(i); //~ ERROR mutable variables cannot be implicitly captured
     }
 }