There are a couple of places that create fake configuration string arrays to pass *wt_checkpoint so that *wt_checkpoint thinks it's a checkpoint, not a file close. This is because we use __wt_schema_worker() to call __wt_checkpoint and there's no way to pass flags through __wt_schema_worker() to the underlying function.

Fix this by creating two underlying functions, *wt_checkpoint and *wt_checkpoint_close, both of which can call __wt_checkpoint_worker() with the right flags, and quit generating fake configuration strings in the places we're doing that.