Small review comment on pg_checksums

Hi,

While reading the pg_checksums code I found the following comment
"Check if cluster is running" is not placed at right place.

    /* Check if cluster is running */
    ControlFile = get_controlfile(DataDir, &crc_ok);
    if (!crc_ok)
    {
        pg_log_error("pg_control CRC value is incorrect");
        exit(1);
    }

    if (ControlFile->pg_control_version != PG_CONTROL_VERSION)
    {
        pg_log_error("cluster is not compatible with this version of
pg_checksums");
        exit(1);
    }

    if (ControlFile->blcksz != BLCKSZ)
    {
        pg_log_error("database cluster is not compatible");
        fprintf(stderr, _("The database cluster was initialized with
block size %u, but pg_checksums was compiled with block size %u.\n"),
                ControlFile->blcksz, BLCKSZ);
        exit(1);
    }

    if (ControlFile->state != DB_SHUTDOWNED &&
        ControlFile->state != DB_SHUTDOWNED_IN_RECOVERY)
    {
        pg_log_error("cluster must be shut down");
        exit(1);
    }

So I'd like to propose a small fix for that; move the comment to the
right place and add another comment. Please find an attached small
patch.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center