update annotate-rs tests

Author: Kivooeo

tests/ui/annotate-snippet/missing-type.rs

@@ -1,5 +1,5 @@
 //@ edition: 2015
-//@ compile-flags: --error-format human-annotate-rs -Z unstable-options
+//@ compile-flags: --error-format human
 
 pub fn main() {
     let x: Iter;

tests/ui/annotate-snippet/multiple-files.rs

@@ -1,5 +1,5 @@
 //@ aux-build:other_file.rs
-//@ compile-flags: --error-format human-annotate-rs -Z unstable-options
+//@ compile-flags: --error-format human
 
 extern crate other_file;
 

tests/ui/annotate-snippet/multispan.rs

@@ -1,5 +1,5 @@
 //@ proc-macro: multispan.rs
-//@ compile-flags: --error-format human-annotate-rs -Z unstable-options
+//@ compile-flags: --error-format human
 
 #![feature(proc_macro_hygiene)]