Set zstd as recommented for kexec-tools
    
    resolves: bz1896698
    upstream: fedora
    conflict: none
    
    commit b8ec5cbda89610244fdd4711e5974350f78e63e3
    Author: Tao Liu <ltao@redhat.com>
    Date:   Fri Jan 7 19:47:06 2022 +0800
    
        Set zstd as recommented for kexec-tools
    
        This patch will make zstd as recommended instead of required for
        kexec-tools. If zstd command/package is unavaliable, it can failback to invoke
        gzip when making kdump initramfs.
    
        Fixes: 0311f6e ("Set zstd as the default compression method for kdump initrd")
    
        Signed-off-by: Tao Liu <ltao@redhat.com>
        Acked-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Tao Liu <ltao@redhat.com>