add failure-status: 1 to the test

Author: nikomatsakis

src/test/run-fail/rfc-1937-termination-trait/termination-trait-for-str.rs

@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // error-pattern: An error message for you
+// failure-status: 1
 
 fn main() -> Result<(), &'static str> {
     Err("An error message for you")