libmakepkg: fix is_array function

This happened to work for the majority of cases because the only calling
function used a variable named "i" that was related to the variable being
passed to the function.

Fixes FS#48340.

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

scripts/libmakepkg/util/util.sh

@@ -46,7 +46,7 @@ is_array() {
 	local shellopts=$(shopt -p)
 	shopt -s extglob
 
-	if [[ $(declare -p "$i") == declare\ -*([[:alnum:]])a*([[:alnum:]])\ * ]]; then
+	if [[ $(declare -p "$v") == declare\ -*([[:alnum:]])a*([[:alnum:]])\ * ]]; then
 		ret=0
 	fi