Fix Decode test Errorf argument order

[HNO3Miracle]

The Decode array-to-struct test currently passes the error string and input value to t.Errorf in the wrong order.

This makes the failure output misleading and can also be reported by newer Go vet checks because the argument types do not match the format string intent.

I have a one-line test-only fix ready that swaps the arguments so the message matches the format string.

[fxamacker]

Thanks for the report.

The reported issue is valid, but this repo no longer accepts pull requests for changes that don't affect library behavior, such as updates to test output messages or rewording comments. Cleanups of that kind are handled by a maintainer during routine maintenance.

This issue will be addressed by a maintainer as part of a larger PR.

Thanks again.