Fix failing test case

Author: tapanprakasht

tests/ui/parser/byte-literals.stderr

@@ -46,13 +46,10 @@ error: non-ASCII character in byte literal
   --> $DIR/byte-literals.rs:10:7
    |
 LL |     b'é';
-   |       ^ must be ASCII
-   |
-help: if you meant to use the unicode code point for 'é', use a \xHH escape
-   |
-LL -     b'é';
-LL +     b'\xE9';
-   |
+   |       ^
+   |       |
+   |       must be ASCII
+   |       this multibyte character does not fit into a single byte
 
 error[E0763]: unterminated byte constant
   --> $DIR/byte-literals.rs:11:6