pgsql: Rename hook functions for debug_io_direct to match variable name

Rename hook functions for debug_io_direct to match variable name. Commit 319bae9a renamed the GUC. Rename the check and assign functions to match, and alphabetize. Back-patch to 16. Author: Peter Eisentraut Discussion: https://postgr.es/m/2769341e-fa28-c2ee-3e4b-53fdcaaf2271%40eisentraut.org

pgsql: Rename hook functions for debug_io_direct to match variable name

Rename hook functions for debug_io_direct to match variable name. Commit 319bae9a renamed the GUC. Rename the check and assign functions to match, and alphabetize. Back-patch to 16. Author: Peter Eisentraut Discussion: https://postgr.es/m/2769341e-fa28-c2ee-3e4b-53fdcaaf2271%40eisentraut.org