new: dev: [docker-builder] put all temp dirs in one.

precise/docker-builder/src/usr/local/bin/docker-update

@@ -49,8 +49,10 @@ clean_all() {
    [ -d "$tmpdir_changes" ] && rm -rf "$tmpdir_changes"
 }
 
-tmpdir_changes=$(mktemp -d /tmp/$COMPONENT_NAME.changes.XXXXXX)
-tmpdir_root=$(mktemp -d /tmp/$COMPONENT_NAME.root.XXXXXX)
+tmpdir="$DOCKER_UPDATE_PATH"/tmp
+mkdir -p "$tmpdir"
+tmpdir_changes=$(mktemp -d $tmpdir/$COMPONENT_NAME.changes.XXXXXX)
+tmpdir_root=$(mktemp -d $tmpdir/$COMPONENT_NAME.root.XXXXXX)
 
 trap "clean_all" EXIT
 mount -t aufs -o br=$tmpdir_changes:$DOCKER_UPDATE_PATH/$COMPONENT_NAME -o udba=none  none "$tmpdir_root"