update image build shell script

guowenxue

2021-12-15 65e1b5a28394ef15fb2939850e154aaa7695e666

 bsp/images/build.sh

@@ -193,6 +193,7 @@
    install_rootfs

    msg_banner " bzip2 compress system image "
    rm -f ${IMAGE_NAME}*.bz2
    bzip2 ${IMAGE_NAME}

    rm -rf ${MNT_POINT}