E0423 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0423.rs

E0423 needs a span_label, updating it from:

error[E0423]: `Foo` is the name of a struct or struct variant, but this expression uses it like a function name
  --> src/test/compile-fail/E0423.rs:14:13
   |
14 |     let f = Foo(); //~ ERROR E0423
   |             ^^^
   |
   = help: did you mean to write: `Foo { /* fields */ }`?

To:

error[E0423]: `Foo` is the name of a struct or struct variant, but this expression uses it like a function name
  --> src/test/compile-fail/E0423.rs:14:13
   |
14 |     let f = Foo(); //~ ERROR E0423
   |             ^^^ struct called like a function
   |
   = help: did you mean to write: `Foo { /* fields */ }`?

[bstrie]

Fixed by #35820.