Update error messages in compile-fail tests

src/test/compile-fail/deriving-span-Zero-tuple-struct.rs

@@ -16,11 +16,9 @@ extern crate rand;
 
 struct Error;
 
-#[deriving(Zero)]   //~ ERROR failed to find an implementation
+#[deriving(Zero)]   //~ ERROR not implemented
 struct Struct(
-    Error //~ ERROR
-    //~^ ERROR failed to find an implementation
-    //~^^ ERROR type `Error` does not implement any method in scope
+    Error
 );
 
 fn main() {}