Fix the sync issue for dump_fs
    
    related: bz2083475
    upstream: fedora
    conflict: none
    
    commit bea61431785def6a10aaf55b4c15657d9ad0ca32
    Author: Tao Liu <ltao@redhat.com>
    Date:   Sat Oct 8 14:53:21 2022 +0800
    
        Fix the sync issue for dump_fs
    
        Previously the sync for dump_fs is problematic, it always
        return success according to man 2 sync. So it cannot detect
        the error of the dump target is full and not all of vmcore
        data been written back the disk, which will leave the vmcore
        imcomplete and report misleading log as "saving vmcore
        complete".
    
        In this patch, we will use "sync -f vmcore" instead, which
        will return error if syncfs on the dump target fails. In
        this way, vmcore sync related failures, such as autoextend
        of lvm2 thinpool fails, can be detected and handled properly.
    
        Signed-off-by: Tao Liu <ltao@redhat.com>
        Reviewed-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Tao Liu <ltao@redhat.com>