pgsql: Fix pg_amcheck --skip option parameter handling

Fix pg_amcheck --skip option parameter handling

The skip options set for all-visible and all-frozen were incorrect
as they used space rather than hyphen, causing a syntax error when
invoked. Also, the option for not skipping any pages at all, none,
was documented but not implemented.

Backpatch through 14 where pg_amcheck was introduced.

Bug: #17149
Reported-by: Chen Jiaoqian <chenjq.jy@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: /messages/by-id/17149-5918ea748da36b15@postgresql.org
Backpatch-through: 14

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/500256d953444628164f0b77ef1ce8c9e05e575f

Modified Files
--------------
src/bin/pg_amcheck/pg_amcheck.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)