BUG #17149: About --skip option of pg_amcheck command

The following bug has been logged on the website:

Bug reference:      17149
Logged by:          Chen Jiaoqian
Email address:      chenjq.jy@fujitsu.com
PostgreSQL version: 14beta3
Operating system:   Red Hat Enterprise Linux Server release 7.8
Description:

Hi, Author

    In PG14 beta3, when I use pg_amcheck command and specify the value of
the option --skip as "none", "all-visible" or "all-frozen", an error
occurs.
    The official website is described as follows:
    > --skip=option
    >   If all-frozen is given, table corruption checks will skip over pages
in all tables that are marked as all frozen.
    >   If all-visible is given, table corruption checks will skip over
pages in all tables that are marked as all visible.
    >   By default, no pages are skipped. This can be specified as none, but
since this is the default, it need not be mentioned.
    
    When I specify the "none" value for --skip option, the following error
occurs:
        [postgres14@localhost ~]$ pg_amcheck -p 51403 -d postgres -t tb01
--skip=none
        pg_amcheck: error: invalid argument for option --skip
        [postgres14@localhost ~]$

    When I specify the "all-visible" or "all-frozen" value for --skip
option, take "all-visible" as an example, the following error occurs:
        [postgres14@localhost ~]$ pg_amcheck -p 51403 -d postgres -t tb01
--skip=all-visible
        2021-08-16 04:59:04.571 EDT [4689] ERROR:  invalid skip option
        2021-08-16 04:59:04.571 EDT [4689] HINT:  Valid skip options are
"all-visible", "all-frozen", and "none".
        2021-08-16 04:59:04.571 EDT [4689] STATEMENT:  SELECT blkno, offnum,
attnum, msg FROM "public".verify_heapam(
                relation := 16396, on_error_stop := false, check_toast :=
true, skip := 'all visible')
        heap table "postgres"."public"."tb01":
            ERROR:  invalid skip option
            HINT:  Valid skip options are "all-visible", "all-frozen", and
"none".
        [postgres14@localhost ~]$

Regards.