update fadump-howto
    
    Resolves: bz2059492
    Upstream: Fedora
    Conflict: None
    
    commit 695e5b8676ecbdf999ed535eae4074db8c3ef7aa
    Author: Coiby Xu <coxu@redhat.com>
    Date:   Tue Mar 1 17:30:30 2022 +0800
    
        update fadump-howto
    
        1. yum is deprecated so use dnf instead
        2. use the "kdumpctl reset-crashkernel --fadump=on" API
    
        Reviewed-by: Philipp Rudo <prudo@redhat.com>
        Signed-off-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Coiby Xu <coxu@redhat.com>