E0454 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0454.rs

E0454 needs a span_label, updating it from:

error[E0454]: #[link(name = "")] given with empty name
  --> src/test/compile-fail/E0454.rs:11:1
   |
11 | #[link(name = "")] extern {} //~ ERROR E0454
   | ^^^^^^^^^^^^^^^^^^

To:

error[E0454]: #[link(name = "")] given with empty name
  --> src/test/compile-fail/E0454.rs:11:1
   |
11 | #[link(name = "")] extern {} //~ ERROR E0454
   | ^^^^^^^^^^^^^^^^^^ empty name given