refactor(iso): Globally define name of settings file (#21)

setup.sh

@@ -19,9 +19,10 @@ exec 3>&1
 declare this_script_url
 this_script_url="${SCRIPT_URL:?}"
 
-declare zpool_name zfs_arch_dataset_name
+declare zpool_name zfs_arch_dataset_name settings_file
 zpool_name='zpool'
 zfs_arch_dataset_name='archlinux'
+settings_file='archzbm_settings.env'
 
 declare -A partition_types
 partition_types[gpt_zfs]='6a85cf4d-1dd2-11b2-99a6-080020736631'
@@ -330,7 +331,6 @@ function load_settings_file () {
     #1.8
     local working_dir settings_file settings_abs
     working_dir="$(pwd)"
-    settings_file='archzbm_settings.env'
     settings_abs="${working_dir}"'/'"${settings_file}"
     if [[ -r "${settings_abs}" ]]; then
         set -a