PatternBadtype: fix order in error message

[paulpatault]

No description provided.

[paulpatault]

I had Error: This pattern has type int but is expected to have type string on

type t = { n : int }

(*@ function f (x: t): unit =
    match x with
    | { n="x" } -> () *)

I think the opposite was expected.

[pascutto]

It does seem right indeed, thanks!