makepkg: fix variable backup/restore for splitpkg

The backup and restore of variables that can be overridden while
making split packages only dealt with the first element, not the
whole array (FS#15010).  Adjust the bash voodoo to fix it...

Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>

scripts/makepkg.sh.in

@@ -1262,7 +1262,7 @@ devel_update() {
 backup_package_variables() {
 	for var in ${splitpkg_overrides[@]}; do
 		indirect="${var}_backup"
-		eval "${indirect}=\"${!var}\""
+		eval "${indirect}=(\${$var[@]})"
 	done
 }
 
@@ -1270,7 +1270,7 @@ restore_package_variables() {
 	for var in ${splitpkg_overrides[@]}; do
 		indirect="${var}_backup"
 		if [ -n "${!indirect}" ]; then
-			eval "${var}=\"${!indirect}\""
+			eval "${var}=(\${$indirect[@]})"
 		else
 			unset ${var}
 		fi