[PATCH]Add a tip to the check mode

Hi community,
when I learn the source of PostgreSQL, I think it's better to add a tip to the postgres "check mode", this can help the postgres's user when they check the postgres's data directory.

src/backend/bootstrap/bootstrap.c

if (check_only)
    {
        SetProcessingMode(NormalProcessing);
        CheckerModeMain();
        abort();
    }

Instead of

if (check_only)
    {
        SetProcessingMode(NormalProcessing);
        CheckerModeMain();
        printf("PostgreSQL check success, there's no problem\n");

        abort();
    }

Yours,
Wen Yi