[fix] : Fixed cowspace

Author: Hayao0819

system/initcpio/hooks/archiso

@@ -172,7 +172,7 @@ run_hook() {
     # shellcheck disable=SC2154
     # defined via initcpio's parse_cmdline()
     [ -z "${archisodevice}" ] && archisodevice="/dev/disk/by-label/${archisolabel}"
-    [ -z "${cow_spacesize}" ] && cow_spacesize="256M"
+    [ -z "${cow_spacesize}" ] && cow_spacesize="%COWSPACE%"
     # shellcheck disable=SC2154
     # defined via initcpio's parse_cmdline()
     if [ -n "${cow_label}" ]; then