pgsql: pg_walsummary: Fix --quiet to suppress limit block output

pg_walsummary: Fix --quiet to suppress limit block output

Previously, pg_walsummary printed limit block lines even with --quiet
because the output was generated before checking the quiet flag.

Fix this by moving the output after the quiet check.

Backpatch to v17, where pg_walsummary was introduced.

Author: Koshi Shibagaki <shibagaki(dot)koshi(at)fujitsu(dot)com>
Reviewed-by: Hayato Kuroda <kuroda(dot)hayato(at)fujitsu(dot)com>
Reviewed-by: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Discussion: https://postgr.es/m/TY5PR01MB18445D1AF87F64E9835BAD0B0FA962@TY5PR01MB18445.jpnprd01.prod.outlook.com
Backpatch-through: 17

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/2a8ce0f684a4aa3da8f8c6f2d255048d545e96ff

Modified Files
--------------
src/bin/pg_walsummary/pg_walsummary.c | 12 ++++++------
src/bin/pg_walsummary/t/002_blocks.pl | 12 ++++++++++++
2 files changed, 18 insertions(+), 6 deletions(-)