pgsql: pg_verify_checksums: rename -d to --verbose

pg_verify_checksums: rename -d to --verbose

Using -d is odd, because we normally reserve that for a database
argument, so rename it to -v and add long version --verbose.

Also, reduce it to emit one line per file checked rather than one line
per block.

Per a complaint from Michael Banck.

Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Michael Banck <michael.banck@credativ.de>
Discussion: https://postgr.es/m/20180827113411.GA22768@nighthawk.caipicrew.dd-dns.de

Branch
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REL_11_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/a840a8ac7b8ab5f8cb86627779d7b1250cdaca8d

Modified Files
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doc/src/sgml/ref/pg_verify_checksums.sgml         |  5 +++--
src/bin/pg_verify_checksums/pg_verify_checksums.c | 18 ++++++++++--------
2 files changed, 13 insertions(+), 10 deletions(-)