abuild: fix check_depends_dev

abuild.in

@@ -747,15 +747,16 @@ check_maintainer() {
 }
 
 check_depends_dev() {
-	if [ -n "$depends_dev" ]; then
+	if [ -z "$depends_dev" ]; then
-		local pkgname
+		return 0
-		for i in $pkgname $subpackages; do
-			case "$pkgname" in
-				*-dev)  return 0 ;;
-			esac
-		done
-		return 1
 	fi
+	local i
+	for i in $pkgname $subpackages; do
+		case "$i" in
+			*-dev)  return 0 ;;
+		esac
+	done
+	return 1
 }
 
 prepare_metafiles() {