kdumpctl: remove unnecessary uses of $?
    
    Resolves: bz2232499
    Upstream: Fedora Rawhide
    Conflict: None
    
    commit b49083126fcdd5be8cb7d84e0048ac2adddb6aed
    Author: Philipp Rudo <prudo@redhat.com>
    Date:   Fri Mar 25 15:47:00 2022 +0100
    
        kdumpctl: remove unnecessary uses of $?
    
        Signed-off-by: Philipp Rudo <prudo@redhat.com>
        Reviewed-by: Tao Liu <ltao@redhat.com>
        Reviewed-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Lichen Liu <lichliu@redhat.com>