update: use DISTDIR directly

leaf

@@ -320,7 +320,7 @@ leaf_update_environment() {
 
 leaf_prepare_package() {
   local url sourcefile index _md5sum
-  distdir="${DIST_DIR}/${pkgname}-${pkgver}"
+  distdir="${DIST_DIR}"
   mkdir -pv "${distdir}"
   pushd "${distdir}"
     for index in "${!sources[@]}"; do