fix: update image path

pack-ci.sh

@@ -70,7 +70,7 @@ unpack_and_mount_image() {
         aml_image_v2_packer -d "$img" "$build_dir"
     else
         is_amlogic=0
-        img_unpack "$img" "${build_dir}/${img}-update.img"
+        img_unpack "$img" "${build_dir}/$(basename "$img")-update.img"
         mkdir "$build_dir/img_dir"
         afptool -unpack "${build_dir}/${img}-update.img" "$build_dir/img_dir"
         systemfile="$build_dir/img_dir/Image/system.img"